Nickel inks and oxidation resistant and conductive coatings

ABSTRACT

A conductive ink may include a nickel component, a polycarboxylic acid component, and a polyol component, the polycarboxylic acid component and the polyol component being reactable to form a polyester component. The polyester component may be formed in situ in the conductive ink from a polyol component and a polycarboxylic acid component. The conductive ink may include a carbon component. The conductive ink may include an additive component. The conductive ink may include nickel flakes, graphene flakes, glutaric acid, and ethylene glycol. The conductive ink may be printed (e.g., screen printed) on a substrate and cured to form a conductive film. A conductive film may include a nickel component and a polyester component.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/655,557, now U.S. Pat. No. 9,416,290, which is a United Statesnational stage under 35 U.S.C. §371 of PCT Patent Application No.PCT/US2013/078059, entitled “NICKEL INKS AND OXIDATION RESISTANT ANDCONDUCTIVE COATINGS,” filed Dec. 27, 2013, which claims the benefit ofU.S. Provisional Patent Application Ser. No. 61/747,093, filed Dec. 28,2012, entitled “NICKEL INKS AND OXIDATION RESISTANT AND CONDUCTIVECOATINGS,” each of which is incorporated herein by reference in itsentirety.

BACKGROUND

Field

This application relates to a conductive ink, particularly to aconductive ink including nickel.

Description of the Related Art

The most common and highest performing conductive inks available on themarket are silver inks. The biggest downside of these inks is cost dueto silver content (varying from 1 to 2 dollars per gram). Copper inksare also available and are cheaper than silver inks; however, the copperinks themselves and the films printed using the copper inks are prone tooxidation and corrosion.

Nickel (Ni) has inherent metal conductivity, high resistance tooxidation and other types of corrosion, and is magnetic. Based on theseproperties, Ni inks find applications in many areas including conductiveinks, decorative metallic paints, corrosion resistant coatings,antistatic coatings, and in radio frequency and electromagneticshielding coatings.

Conductive screen printable Ni inks available on the market have a rangeof sheet resistance between about 5 Ohm/sq/mil and about 300 Ohm/sq/mil,which is relatively high compared to what one would expect from a metalink. The relatively low conductivity of existing Ni inks might alsoexplain why there are not many suppliers of such materials (e.g.,existing suppliers include Creative Materials, Corp., Gwent ElectronicMaterials, Ltd., Engineered Conductive Materials, LLC, and Epoxies,etc.). There are also existing suppliers producing ink-jet printablenano Ni inks (e.g., Applied Nanotech Holdings, Inc.). Although, nanoinkscured at temperatures above 300° C. are highly conductive (e.g., theycan become a thin metal film after curing), they are expensive and notapplicable where a thicker coating or lower curing temperatures areneeded. They are also more difficult to produce in large quantities dueto the nanomaterials.

Therefore, there is a need for Ni ink having improved properties.

SUMMARY

A conductive ink may include a nickel component, a polycarboxylic acidcomponent, and a polyol component, the polycarboxylic acid component andthe alcohol polyol component being reactable to form a polyestercomponent. The conductive ink may include an additive component and/or acarbon component.

In some embodiments, the nickel component can include at least one ofnickel flakes, nickel nano/microwires, and nickel spheres. The nickelflakes may have a thickness of less than about 5 microns. The nickelflakes may have a diameter of about 100 nanometers to about 50 microns.The nickel flakes may have a diameter of about 500 nanometers to about30 microns.

In some embodiments, the nickel component may be a filamentary nickelpowder. The filamentary nickel powder may have a longest dimension in arange of about 2 microns to about 10 microns.

In some embodiments, the nickel component can have at least one particlehaving a longest dimension in a range of about 0.5 microns to about 50microns. The nickel component may have at least one particle with alongest dimension in a range of about 0.5 microns to about 30 microns.The nickel component may have at least one particle with a longestdimension in a range of about 5 microns to about 20 microns.

The carbon component may include at least one of carbon flakes, carbonnano/microwires, and carbon spheres. The carbon component may have atleast one of graphene, graphite, activated carbon, carbon nanotubes, andcarbon nanofibers. The graphite may include a graphite powder. Thegraphene may include graphene flakes. In some embodiments, at least oneof the graphene flakes may have a diameter of about 5 microns. In someembodiments, at least one of the graphene flakes may have a diameter ofabout 100 nanometers to about 50 microns.

In some embodiments, the polycarboxylic acid component can include adicarboxylic acid. For example, the dicarboxylic acid may include atleast one of a propanedioic (malonic) acid, a butanedioic (succinic)acid, a pentanedioic (glutaric) acid, a hexanedioic (adipic) acid, aheptanedioic (pimelic) acid, a octanedioic (suberic) acid, a nonanedioic(azelaic) acid, a decanedioic (sebacic) acid, an undecanedioic acid, adodecanedioic acid, a tridecanedioic (brassylic) acid, atetradecanedioic acid, a pentadecanedioic acid, a hexadecanedioic(thapsic) acid, an octadecanedioic acid, a maleic acid, a fumaric acid,a glutaconic acid, a traumatic acid and a muconic acid.

In some embodiments, the polycarboxylic acid component can include atricarboxylic acid. For example, the tricarboxylic acid may include atleast one of a citric acid, an isocitric acid, an aconitic acid, acarballylic acid, a trimesic acid, and a terephthalic acid.

In some embodiments, the polycarboxylic acid component can include ahydroxicarboxilic acid. For example, the hydroxicarboxilic acid mayinclude at least one of a 4-hydroxybenzoic acid, a glycolic acid, alactic acid, citric acid, a mandelic acid, a beta hydroxy acid, an omegahydroxy acid, a salicylic acid, a 3-hydroxypropionic acid, and a6-hydroxynaphthalene-2-carboxylic acid.

The polyol component may include at least one of a glycerol and aglycol. In some embodiments, the polyol component can include at leastone of a glycerin, a diol, a triol, a tetraol, a pentaol, an ethyleneglycol, a diethylene glycol, a polyethylene glycol, a propylene glycol,a dipropylene glycol, a glycol ether, a glycol ether acetates1,4-butanediol, a 1,2-butanediol, a 2,3-butanediol, a 1,3-propanediol, a1,4-butanediol, a 1,5-pentanediol, a 1,8-octanediol, a 1,2-propanediol,a 1,3-butanediol, a 1,2-pentanediol, an etohexadiol, ap-menthane-3,8-diol, and a 2-methyl-2,4-pentanediol.

The additive component may include at least one of a viscosity modifier,a wetting agent, a flow and leveling agent, an adhesion promoter, and acorrosion inhibitor. For example, the wetting agent may include apolyethylene glycol. For example, the corrosion inhibitor may include atleast one of an N,N-diethylhydroxylamine, an ascorbic acid, a hydrazine,a hexamine, a phenylenediamine, a benzotriazole, a zinc dithiophosphate,a tannic acid, a zinc phosphate, and a hexafluoroacetylacetone.

In some embodiments, the additive component includes a solvent. Thesolvent may include at least one of a viscosity modifier, a wettingagent, a flow and leveling agent, and an adhesion promoter. The solventmay include at least one of an alcohol and water. For example, thealcohol may include at least one of a methanol, an ethanol, aN-propanol, a butanol, pentanol, hexanol, an octanol, an N-octanol, atetrahydrofurfuryl alcohol (THFA), a cyclohexanol, a cyclopentanol, anda terpineol. The N-propanol may include at least one of a 1-propanol, a2-propanol, and a 1-methoxy-2-propanol. The butanol may include at leastone of a 1-butanol and a 2-butanol. The pentanol may include at leastone of a 1-pentanol, a 2-pentanol, and a 3-pentanol. The hexanol mayinclude at least one of a 1-hexanol, a 2-hexanol, and a 3-hexanol. TheN-octanol may include at least one of a 1-octanol, a 2-octanol, and a3-octanol.

In some embodiments, the additive component may include a butyl lactone.In some embodiments, the additive component may include an ether. Theether may include at least one of a methyl ethyl ether, a diethyl ether,an ethyl propyl ether, and a polyether.

In some embodiments, the additive component can include a ketone. Theketone may include at least one of an acetone and a methyl ethyl ketone.In some embodiments, the ketone can include at least one of a diketoneand a cyclic ketone. For example, the cyclic ketone may include at leastone of a cyclohexanone, a cyclopentanone, a cycloheptanone, acyclooctanone, a benzophenone, an acetylacetone, an acetophenone, acyclopropanone, and an isophorone.

In some embodiments, the additive component can include an ester. Theester may include at least one of a dibasic ester, an ethyl acetate, adimethyl adipate, a proplyene glycol monomethyl ether acetate, adimethyl glutarate, a dimethyl succinate, a glycerin acetate, and acarboxylate.

In some embodiments, the additive component can include a carbonate. Thecarbonate may include a propylene carbonate.

In some embodiments, the additive component can include at least one ofa glycol ether, a glycol ether acetate, a tetramethyl urea, ann-methylpyrrolidone, an acetonitrile, a tetrahydrofuran (THF), adimethyl formamide (DMF), an N-methyl formamide (NMF), a dimethylsulfoxide (DMSO), a thionyl chloride, a sulfuryl chloride, a1,2-diaminoethane, a propane-1,3-diamine, a butane-1,4-diamine, apentane-1,5-diamine, a hexane-1,6-diamine, a 1,2-diaminopropane, adiphenylethylenediamine, a diaminocyclohexane, an o-xylylenediamine, ano-phenylenediamine, an m-phenylenediamine, a hexane, a decane, ateradecane, a styrene, a 1-vinyl-2-pyrolidone, a toluene, a pyridine,and a triethyl phosphate.

In some embodiments, the conductive ink has a viscosity at about 25° C.in a range from about 5,000 centipoise to about 11,000 centipoise.

In some embodiments, the nickel component is in a range from about 50 wt% to about 60 wt %. In some embodiments, the nickel component is in arange from about 35 wt % to about 65 wt %.

In some embodiments, the carbon component is in a range from about 0.5wt % to about 2.5 wt %. In some embodiments, the carbon component isless than about 10 wt %.

In some embodiments, the polycarboxylic acid component is in a rangefrom about 5 wt % to about 15 wt %.

In some embodiments, the polyol component is in a range from about 25 wt% to about 40 wt %. In some embodiments, the polyol component is in arange from about 15 wt % to about 60 wt %.

In some embodiments, the additive component is less than about 10%.

A conductive film may include a nickel component and a polyestercomponent. In some embodiments, the conductive film may include anadditive component and/or a carbon component.

In some embodiments, the nickel component can include at least one ofnickel flakes, nickel nano/microwires, and nickel spheres. The nickelflakes may have a thickness of less than about 5 microns. The nickelflakes may have a diameter of about 100 nanometers to about 50 microns.The nickel flakes may have a diameter of about 500 nanometers to about30 microns.

In some embodiments, the nickel component may be a filamentary nickelpowder. The filamentary nickel powder may have a longest dimension in arange of about 2 microns to about 10 microns.

In some embodiments, the nickel component of the conductive film canhave at least one particle having a longest dimension in a range ofabout 100 nanometers to about 50 microns. The nickel component may haveat least one particle with a longest dimension in a range of about 0.5microns to about 30 microns. The nickel component may have at least oneparticle with a longest dimension in a range of about 5 microns to about20 microns.

The carbon component of the conductive film may include at least one ofcarbon flakes, carbon nano/microwires, and carbon spheres. The carboncomponent may have at least one of graphene, graphite, activated carbon,carbon nanotubes, and carbon nanofibers. The graphite may include agraphite powder. The graphene may include graphene flakes. In someembodiments, at least one of the graphene flakes may have a diameter ofabout 5 microns. In some embodiments, at least one of the grapheneflakes may have a diameter of about 100 nanometers to about 50 microns.

In some embodiments, the polyester component of the conductive film canbe formed in situ from a polycarboxylic acid component and a polyolcomponent.

In some embodiments, the conductive film has a sheet resistance in arange from about 0.5 ohm/sq/mil to about 1.5 ohm/sq/mil. In someembodiments, the conductive film has a thickness in a range from about 4microns to about 40 microns.

The conductive film may be printed onto a substrate. Suitable substratesmay include a conductive substrate or a non-conductive substrate. Thesubstrate may include at least one of a graphite paper, a graphenepaper, a polyester film, a polyimide film, an aluminum foil, a copperfoil, a stainless steel foil, a carbon foam, a polycarbonate film, apaper, a coated paper, a plastic coated paper, a fiber paper, and acardboard.

A method of fabricating a conductive ink may include dispersing a nickelcomponent in a solvent component, and dispersing a polyester componentin the solvent component.

The method of fabricating the conductive ink may include dispersing acarbon component in the solvent component. Dispersing the nickelcomponent in the solvent component may be before dispersing thepolyester component in the solvent component. Dispersing the nickelcomponent in the solvent component may be after dispersing the polyestercomponent in the solvent component.

Dispersing the nickel component in the solvent component may be beforedispersing the carbon component in the solvent component. In someembodiments, dispersing the nickel component in the solvent componentcan be after dispersing the carbon component in the solvent component.

In some embodiments, dispersing the carbon component in the solventcomponent can be before dispersing the polyester component in thesolvent component. In some embodiments, dispersing the carbon componentin the solvent component can be after dispersing the polyester componentin the solvent component.

The method of fabricating the conductive ink can include adding anadditive component to the solvent component.

Adding the additive component to the solvent component may be beforedispersing the nickel component in the solvent. Adding the additivecomponent to the solvent component may be after dispersing the nickelcomponent in the solvent. Adding the additive component to the solventcomponent may be before dispersing the polyester component in thesolvent. In some embodiments, adding the additive component to thesolvent component can be after dispersing the polyester component in thesolvent. In some embodiments, adding the additive component to thesolvent component can be before dispersing the carbon component in thesolvent. In some embodiments, adding the additive component to thesolvent component can be after dispersing the carbon component in thesolvent.

The conductive ink may be printable onto a substrate. Suitablesubstrates may include a conductive substrate or a non-conductivesubstrate. The substrate may include at least one of a graphite paper, agraphene paper, a polyester film, a polyimide film, an aluminum foil, acopper foil, a stainless steel foil, a carbon foam, a polycarbonatefilm, a paper, a coated paper, a plastic coated paper, a fiber paper,and a cardboard.

In some embodiments, the nickel component can include at least one ofnickel flakes, nickel nano/microwires, and nickel spheres. The nickelflakes may have a thickness of less than about 5 microns. The nickelflakes may have a diameter of about 100 nanometers to about 50 microns.The nickel flakes may have a diameter of about 500 nanometers to about30 microns.

In some embodiments, the nickel component may be a filamentary nickelpowder. The filamentary nickel powder may have a longest dimension in arange of about 2 microns to about 10 microns.

In some embodiments, the nickel component of the conductive ink can haveat least one particle having a longest dimension in a range of about 100nanometers to about 50 microns. The nickel component may have at leastone particle with a longest dimension in a range of about 0.5 microns toabout 30 microns. The nickel component may have at least one particlewith a longest dimension in a range of about 5 microns to about 20microns.

The carbon component of the conductive ink may include at least one ofcarbon flakes, carbon nano/microwires, and carbon spheres. The carboncomponent may have at least one of graphene, graphite, activated carbon,carbon nanotubes, and carbon nanofibers. The graphite may include agraphite powder. The graphene may include graphene flakes. In someembodiments, at least one of the graphene flakes may have a diameter ofabout 5 microns. In some embodiments, at least one of the grapheneflakes may have a diameter of about 100 nanometers to about 50 microns.

In some embodiments, the polyester component can be formed from apolycarboxylic acid component and a polyol component.

In some embodiments, the polycarboxylic acid component can include adicarboxylic acid. For example, the dicarboxylic acid may include atleast one of a propanedioic (malonic) acid, a butanedioic (succinic)acid, a pentanedioic (glutaric) acid, a hexanedioic (adipic) acid, aheptanedioic (pimelic) acid, a octanedioic (suberic) acid, a nonanedioic(azelaic) acid, a decanedioic (sebacic) acid, an undecanedioic acid, adodecanedioic acid, a tridecanedioic (brassylic) acid, atetradecanedioic acid, a pentadecanedioic acid, a hexadecanedioic(thapsic) acid, an octadecanedioic acid, a maleic acid, a fumaric acid,a glutaconic acid, a traumatic acid and a muconic acid.

In some embodiments, the polycarboxylic acid component can include atricarboxylic acid. For example, the tricarboxylic acid may include atleast one of a citric acid, an isocitric acid, an aconitic acid, acarballylic acid, a trimesic acid, and a terephthalic acid.

In some embodiments, the polycarboxylic acid component can include ahydroxicarboxilic acid. For example, the hydroxicarboxilic acid mayinclude at least one of a 4-hydroxybenzoic acid, a glycolic acid, alactic acid, citric acid, a mandelic acid, a beta hydroxy acid, an omegahydroxy acid, a salicylic acid, a 3-hydroxypropionic acid, and a6-hydroxynaphthalene-2-carboxylic acid.

The polyol component may include at least one of a glycerol and aglycol. In some embodiments, the polyol component can include at leastone of a glycerin, a diol, a triol, a tetraol, a pentaol, an ethyleneglycol, a diethylene glycol, a polyethylene glycol, a propylene glycol,a dipropylene glycol, a glycol ether, a glycol ether acetates1,4-butanediol, a 1,2-butanediol, a 2,3-butanediol, a 1,3-propanediol, a1,4-butanediol, a 1,5-pentanediol, a 1,8-octanediol, a 1,2-propanediol,a 1,3-butanediol, a 1,2-pentanediol, an etohexadiol, ap-menthane-3,8-diol, and a 2-methyl-2,4-pentanediol.

The additive component may include at least one of a viscosity modifier,a wetting agent, a flow and leveling agent, an adhesion promoter, and acorrosion inhibitor. For example, the wetting agent may include apolyethylene glycol. For example, the corrosion inhibitor may include atleast one of an N,N-diethylhydroxylamine, an ascorbic acid, a hydrazine,a hexamine, a phenylenediamine, a benzotriazole, a zinc dithiophosphate,a tannic acid, a zinc phosphate, and a hexafluoroacetylacetone.

In some embodiments, the additive component includes a solvent. Thesolvent may include at least one of a viscosity modifier, a wettingagent, a flow and leveling agent, and an adhesion promoter. The solventmay include at least one of an alcohol and water. For example, thealcohol may include at least one of a methanol, an ethanol, aN-propanol, a butanol, pentanol, hexanol, an octanol, an N-octanol, atetrahydrofurfuryl alcohol (THFA), a cyclohexanol, a cyclopentanol, anda terpineol. The N-propanol may include at least one of a 1-propanol, a2-propanol, and a 1-methoxy-2-propanol. The butanol may include at leastone of a 1-butanol and a 2-butanol. The pentanol may include at leastone of a 1-pentanol, a 2-pentanol, and a 3-pentanol. The hexanol mayinclude at least one of a 1-hexanol, a 2-hexanol, and a 3-hexanol. TheN-octanol may include at least one of a 1-octanol, a 2-octanol, and a3-octanol.

In some embodiments, the additive component may include a butyl lactone.In some embodiments, the additive component may include an ether. Theether may include at least one of a methyl ethyl ether, a diethyl ether,an ethyl propyl ether, and a polyether.

In some embodiments, the additive component can include a ketone. Theketone may include at least one of an acetone and a methyl ethyl ketone.In some embodiments, the ketone can include at least one of a diketoneand a cyclic ketone. For example, the cyclic ketone may include at leastone of a cyclohexanone, a cyclopentanone, a cycloheptanone, acyclooctanone, a benzophenone, an acetylacetone, an acetophenone, acyclopropanone, and an isophorone.

In some embodiments, the additive component can include an ester. Theester may include at least one of a dibasic ester, an ethyl acetate, adimethyl adipate, a proplyene glycol monomethyl ether acetate, adimethyl glutarate, a dimethyl succinate, a glycerin acetate, and acarboxylate.

In some embodiments, the additive component can include a carbonate. Thecarbonate may include a propylene carbonate.

In some embodiments, the additive component can include at least one ofa glycol ether, a glycol ether acetate, a tetramethyl urea, ann-methylpyrrolidone, an acetonitrile, a tetrahydrofuran (THF), adimethyl formamide (DMF), an N-methyl formamide (NMF), a dimethylsulfoxide (DMSO), a thionyl chloride, a sulfuryl chloride, a1,2-diaminoethane, a propane-1,3-diamine, a butane-1,4-diamine, apentane-1,5-diamine, a hexane-1,6-diamine, a 1,2-diaminopropane, adiphenylethylenediamine, a diaminocyclohexane, an o-xylylenediamine, ano-phenylenediamine, an m-phenylenediamine, a hexane, a decane, ateradecane, a styrene, a 1-vinyl-2-pyrolidone, a toluene, a pyridine,and a triethyl phosphate.

In some embodiments, the conductive ink can have a viscosity at about25° C. in a range from about 5,000 centipoise to about 11,000centipoise.

In some embodiments, the nickel component is in a range from about 50 wt% to about 60 wt %. In some embodiments, the method of any one ofembodiments 80 to 143, wherein the nickel component is in a range fromabout 35 wt % to about 65 wt %.

In some embodiments, the carbon component is in a range from about 0.5wt % to about 2.5 wt %. In some embodiments, the carbon component isless than about 10 wt %.

In some embodiments, the additive component is less than about 10 wt %.

A method of fabricating a conductive film may include printing aconductive ink on a substrate. The conductive ink may include a nickelcomponent, and a polyester component. In some embodiments, the method offabricating the conductive film can include curing the printedconductive ink.

Printing the conductive ink may include at least one of a screenprinting process, a coating process, a rolling process, a sprayingprocess, a layering process, a spin coating process, a laminationprocess, an affixing process, an inkjet printing process, anelectro-optical printing process, an electroink printing process, aresist printing process, a thermal printing process, a laser jetprinting process, a magnetic printing process, a pad printing process, aflexographic printing process, a hybrid offset lithography process, aintaglio printing process, and a die slot deposition process.

The screen printing process may include using a polyester screen. Thescreen printing process may include using a polyamide screen. The screenprinting process may include using a screen having a mesh size of about110 or about 135.

The conductive ink may be printable onto a substrate. Suitablesubstrates may include a conductive substrate or a non-conductivesubstrate. The substrate may include at least one of a graphite paper, agraphene paper, a polyester film, a polyimide film, an aluminum foil, acopper foil, a stainless steel foil, a carbon foam, a polycarbonatefilm, a paper, a coated paper, a plastic coated paper, a fiber paper,and a cardboard.

In some embodiments, curing the printed conductive ink can includeheating the printed conductive ink and the substrate to a temperature ina range from about 100° C. to about 200° C. Curing the printedconductive ink may include heating the printed conductive ink and thesubstrate to a temperature in a range from about 130° C. to about 140°C.

In some embodiments, curing the printed conductive ink can includeheating the printed conductive ink and the substrate for a duration fromabout 20 seconds to about 1 hour. In some embodiments, curing theprinted conductive ink can include heating the printed conductive inkand the substrate for a duration from about 3 minutes to about 10minutes.

In some embodiments, the nickel component can include at least one ofnickel flakes, nickel nano/microwires, and nickel spheres. The nickelflakes may have a thickness of less than about 5 microns. The nickelflakes may have a diameter of about 100 nanometers to about 50 microns.The nickel flakes may have a diameter of about 500 nanometers to about30 microns.

In some embodiments, the nickel component may be a filamentary nickelpowder. The filamentary nickel powder may have a longest dimension in arange of about 2 microns to about 10 microns.

In some embodiments, the nickel component of the conductive film canhave at least one particle having a longest dimension in a range ofabout 0.5 microns to about 50 microns. The nickel component may have atleast one particle with a longest dimension in a range of about 0.5microns to about 30 microns. The nickel component may have at least oneparticle with a longest dimension in a range of about 5 microns to about20 microns.

The carbon component of the conductive film may include at least one ofcarbon flakes, carbon nano/microwires, and carbon spheres. The carboncomponent may have at least one of graphene, graphite, activated carbon,carbon nanotubes, and carbon nanofibers. The graphite may include agraphite powder. The graphene may include graphene flakes. In someembodiments, at least one of the graphene flakes may have a diameter ofabout 5 microns. In some embodiments, at least one of the grapheneflakes may have a diameter of about 100 nanometers to about 50 microns.

In some embodiments, the polyester component can be formed from apolycarboxylic acid component and a polyol component.

In some embodiments, the polycarboxylic acid component can include adicarboxylic acid. For example, the dicarboxylic acid may include atleast one of a propanedioic (malonic) acid, a butanedioic (succinic)acid, a pentanedioic (glutaric) acid, a hexanedioic (adipic) acid, aheptanedioic (pimelic) acid, a octanedioic (suberic) acid, a nonanedioic(azelaic) acid, a decanedioic (sebacic) acid, an undecanedioic acid, adodecanedioic acid, a tridecanedioic (brassylic) acid, atetradecanedioic acid, a pentadecanedioic acid, a hexadecanedioic(thapsic) acid, and an octadecanedioic acid, a maleic acid, a fumaricacid, a glutaconic acid, a traumatic acid and a muconic acid.

In some embodiments, the polycarboxylic acid component can include atricarboxylic acid. For example, the tricarboxylic acid may include atleast one of a citric acid, an isocitric acid, an aconitic acid, acarballylic acid, a trimesic acid, and a terephthalic acid.

In some embodiments, the polycarboxylic acid component can include ahydroxicarboxilic acid. For example, the hydroxicarboxilic acid mayinclude at least one of a 4-hydroxybenzoic acid, a glycolic acid, alactic acid, citric acid, a mandelic acid, a beta hydroxy acid, an omegahydroxy acid, a salicylic acid, a 3-hydroxypropionic acid, and a6-hydroxynaphthalene-2-carboxylic acid.

The polyol component may include at least one of a glycerol and aglycol. In some embodiments, the polyol component can include at leastone of a glycerin, a diol, a triol, a tetraol, a pentaol, an ethyleneglycol, a diethylene glycol, a polyethylene glycol, a propylene glycol,a dipropylene glycol, a glycol ether, a glycol ether acetates1,4-butanediol, a 1,2-butanediol, a 2,3-butanediol, a 1,3-propanediol, a1,4-butanediol, a 1,5-pentanediol, a 1,8-octanediol, a 1,2-propanediol,a 1,3-butanediol, a 1,2-pentanediol, an etohexadiol, ap-menthane-3,8-diol, and a 2-methyl-2,4-pentanediol.

In some embodiments, the conductive ink can include an additivecomponent.

The additive component may include at least one of a viscosity modifier,a wetting agent, a flow and leveling agent, an adhesion promoter, and acorrosion inhibitor. For example, the wetting agent may include apolyethylene glycol. For example, the corrosion inhibitor may include atleast one of an N,N-diethylhydroxylamine, an ascorbic acid, a hydrazine,a hexamine, a phenylenediamine, a benzotriazole, a zinc dithiophosphate,a tannic acid, a zinc phosphate, and a hexafluoroacetylacetone.

In some embodiments, the additive component includes a solvent. Thesolvent may include at least one of a viscosity modifier, a wettingagent, a flow and leveling agent, and an adhesion promoter. The solventmay include at least one of an alcohol and water. For example, thealcohol may include at least one of a methanol, an ethanol, aN-propanol, a butanol, pentanol, hexanol, an octanol, an N-octanol, atetrahydrofurfuryl alcohol (THFA), a cyclohexanol, a cyclopentanol, anda terpineol. The N-propanol may include at least one of a 1-propanol, a2-propanol, and a 1-methoxy-2-propanol. The butanol may include at leastone of a 1-butanol and a 2-butanol. The pentanol may include at leastone of a 1-pentanol, a 2-pentanol, and a 3-pentanol. The hexanol mayinclude at least one of a 1-hexanol, a 2-hexanol, and a 3-hexanol. TheN-octanol may include at least one of a 1-octanol, a 2-octanol, and a3-octanol.

In some embodiments, the additive component may include a butyl lactone.In some embodiments, the additive component may include an ether. Theether may include at least one of a methyl ethyl ether, a diethyl ether,an ethyl propyl ether, and a polyether.

In some embodiments, the additive component can include a ketone. Theketone may include at least one of an acetone and a methyl ethyl ketone.In some embodiments, the ketone can include at least one of a diketoneand a cyclic ketone. For example, the cyclic ketone may include at leastone of a cyclohexanone, a cyclopentanone, a cycloheptanone, acyclooctanone, a benzophenone, an acetylacetone, an acetophenone, acyclopropanone, and an isophorone.

In some embodiments, the additive component can include an ester. Theester may include at least one of a dibasic ester, an ethyl acetate, adimethyl adipate, a proplyene glycol monomethyl ether acetate, adimethyl glutarate, a dimethyl succinate, a glycerin acetate, and acarboxylate.

In some embodiments, the additive component can include a carbonate. Thecarbonate may include a propylene carbonate.

In some embodiments, the additive component can include at least one ofa glycol ether, a glycol ether acetate, a tetramethyl urea, ann-methylpyrrolidone, an acetonitrile, a tetrahydrofuran (THF), adimethyl formamide (DMF), an N-methyl formamide (NMF), a dimethylsulfoxide (DMSO), a thionyl chloride, a sulfuryl chloride, a1,2-diaminoethane, a propane-1,3-diamine, a butane-1,4-diamine, apentane-1,5-diamine, a hexane-1,6-diamine, a 1,2-diaminopropane, adiphenylethylenediamine, a diaminocyclohexane, an o-xylylenediamine, ano-phenylenediamine, an m-phenylenediamine, a hexane, a decane, ateradecane, a styrene, a 1-vinyl-2-pyrolidone, a toluene, a pyridine,and a triethyl phosphate.

The conductive ink comprises a viscosity at 25° C. in a range from about5,000 centipoise to about 11,000 centipoise.

In some embodiments, the nickel component of the conductive film can bein a range from about 50 wt % to about 60 wt %. In some embodiments, thenickel component can be is in a range from about 35 wt % to about 65 wt%.

In some embodiments, the carbon component can be in a range from about0.5 wt % to about 2.5 wt %. In some embodiments, the carbon component ofthe conductive film can be less than about 10 wt %.

In some embodiments, the additive component can be less than about 10 wt%.

A method of fabricating a conductive ink may include dispersing a nickelcomponent in an alcohol polyol component, and dispersing anpolycarboxylic acid component in the alcohol polyol component, where thepolycarboxylic acid component and the alcohol polyol component arereactable to form a polyester component.

In some embodiments, dispersing the polycarboxylic acid component in thepolyol component forms the polyester component in situ.

In some embodiments, the method of fabricating a conductive ink caninclude dispersing a carbon component in the polyol component.

Dispersing the nickel component in the polyol component can be beforedispersing the polycarboxylic acid component in the polyol component.Dispersing the nickel component in the polyol component can be afterdispersing the polycarboxylic acid component in the polyol component.

In some embodiments, dispersing the nickel component in the polyolcomponent can be before dispersing the carbon component in the polyolcomponent. In some embodiments, dispersing the nickel component in thepolyol component can be after dispersing the carbon component in thepolyol component.

In some embodiments, dispersing the carbon component in the polyolcomponent can be before dispersing the polycarboxylic acid component inthe polyol component. In some embodiments, dispersing the carboncomponent in the polyol component can be after dispersing thepolycarboxylic acid component in the polyol component.

The method of fabricating a conductive ink can include adding anadditive component.

In some embodiments, adding the additive component can be beforedispersing the nickel component in the polyol component. In someembodiments, adding the additive component can be after dispersing thenickel component in the polyol component. In some embodiments, addingthe additive component can be before dispersing the polycarboxylic acidcomponent in the polyol component. In some embodiments, adding theadditive component can be after dispersing the polycarboxylic acidcomponent in the polyol component. In some embodiments, adding theadditive component can be before dispersing the carbon component in thepolyol component. In some embodiments, adding the additive component canbe after dispersing the carbon component in the polyol component.

The conductive ink may be printable onto a substrate. Suitablesubstrates may include a conductive substrate or a non-conductivesubstrate. For example, a substrate may include at least one of agraphite paper, a graphene paper, a polyester film, a polyimide film, analuminum foil, a copper foil, a stainless steel foil, a carbon foam, apolycarbonate film, a paper, a coated paper, a plastic coated paper, afiber paper, and a cardboard.

In some embodiments, the nickel component can include at least one ofnickel flakes, nickel nano/microwires, and nickel spheres. The nickelflakes may have a thickness of less than about 5 microns. The nickelflakes may have a diameter of about 100 nanometers to about 50 microns.The nickel flakes may have a diameter of about 500 nanometers to about30 microns.

In some embodiments, the nickel component may be a filamentary nickelpowder. The filamentary nickel powder may have a longest dimension in arange of about 2 microns to about 10 microns.

In some embodiments, the nickel component can have at least one particlehaving a longest dimension in a range of about 0.5 microns to about 50microns. The nickel component may have at least one particle with alongest dimension in a range of about 0.5 microns to about 30 microns.The nickel component may have at least one particle with a longestdimension in a range of about 5 microns to about 20 microns.

The carbon component may include at least one of carbon flakes, carbonnano/microwires, and carbon spheres. The carbon component may have atleast one of graphene, graphite, activated carbon, carbon nanotubes, andcarbon nanofibers. The graphite may include a graphite powder. Thegraphene may include graphene flakes. In some embodiments, at least oneof the graphene flakes may have a diameter of about 5 microns. In someembodiments, at least one of the graphene flakes may have a diameter ofabout 100 nanometers to about 50 microns.

In some embodiments, the polycarboxylic acid component can include adicarboxylic acid. For example, the dicarboxylic acid may include atleast one of a propanedioic (malonic) acid, a butanedioic (succinic)acid, a pentanedioic (glutaric) acid, a hexanedioic (adipic) acid, aheptanedioic (pimelic) acid, a octanedioic (suberic) acid, a nonanedioic(azelaic) acid, a decanedioic (sebacic) acid, an undecanedioic acid, adodecanedioic acid, a tridecanedioic (brassylic) acid, atetradecanedioic acid, a pentadecanedioic acid, a hexadecanedioic(thapsic) acid, and an octadecanedioic acid, a maleic acid, a fumaricacid, a glutaconic acid, a traumatic acid and a muconic acid.

In some embodiments, the polycarboxylic acid component can include atricarboxylic acid. For example, the tricarboxylic acid may include atleast one of a citric acid, an isocitric acid, an aconitic acid, acarballylic acid, a trimesic acid, and a terephthalic acid.

In some embodiments, the polycarboxylic acid component can include ahydroxicarboxilic acid. For example, the hydroxicarboxilic acid mayinclude at least one of a 4-hydroxybenzoic acid, a glycolic acid, alactic acid, citric acid, a mandelic acid, a beta hydroxy acid, an omegahydroxy acid, a salicylic acid, a 3-hydroxypropionic acid, and a6-hydroxynaphthalene-2-carboxylic acid.

The polyol component may include at least one of a glycerol and aglycol. In some embodiments, the polyol component can include at leastone of a glycerin, a diol, a triol, a tetraol, a pentaol, an ethyleneglycol, a diethylene glycol, a polyethylene glycol, a propylene glycol,a dipropylene glycol, a glycol ether, a glycol ether acetates1,4-butanediol, a 1,2-butanediol, a 2,3-butanediol, a 1,3-propanediol, a1,4-butanediol, a 1,5-pentanediol, a 1,8-octanediol, a 1,2-propanediol,a 1,3-butanediol, a 1,2-pentanediol, an etohexadiol, ap-menthane-3,8-diol, and a 2-methyl-2,4-pentanediol.

The additive component may include at least one of a viscosity modifier,a wetting agent, a flow and leveling agent, an adhesion promoter, and acorrosion inhibitor. For example, the wetting agent may include apolyethylene glycol. For example, the corrosion inhibitor may include atleast one of an N,N-diethylhydroxylamine, an ascorbic acid, a hydrazine,a hexamine, a phenylenediamine, a benzotriazole, a zinc dithiophosphate,a tannic acid, a zinc phosphate, and a hexafluoroacetylacetone.

In some embodiments, the additive component includes a solvent. Thesolvent may include at least one of a viscosity modifier, a wettingagent, a flow and leveling agent, and an adhesion promoter. The solventmay include at least one of an alcohol and water. For example, thealcohol may include at least one of a methanol, an ethanol, aN-propanol, a butanol, pentanol, hexanol, an octanol, an N-octanol, atetrahydrofurfuryl alcohol (THFA), a cyclohexanol, a cyclopentanol, anda terpineol. The N-propanol may include at least one of a 1-propanol, a2-propanol, and a 1-methoxy-2-propanol. The butanol may include at leastone of a 1-butanol and a 2-butanol. The pentanol may include at leastone of a 1-pentanol, a 2-pentanol, and a 3-pentanol. The hexanol mayinclude at least one of a 1-hexanol, a 2-hexanol, and a 3-hexanol. TheN-octanol may include at least one of a 1-octanol, a 2-octanol, and a3-octanol.

In some embodiments, the additive component may include a butyl lactone.In some embodiments, the additive component may include an ether. Theether may include at least one of a methyl ethyl ether, a diethyl ether,an ethyl propyl ether, and a polyether.

In some embodiments, the additive component can include a ketone. Theketone may include at least one of an acetone and a methyl ethyl ketone.In some embodiments, the ketone can include at least one of a diketoneand a cyclic ketone. For example, the cyclic ketone may include at leastone of a cyclohexanone, a cyclopentanone, a cycloheptanone, acyclooctanone, a benzophenone, an acetylacetone, an acetophenone, acyclopropanone, and an isophorone.

In some embodiments, the additive component can include an ester. Theester may include at least one of a dibasic ester, an ethyl acetate, adimethyl adipate, a proplyene glycol monomethyl ether acetate, adimethyl glutarate, a dimethyl succinate, a glycerin acetate, and acarboxylate.

In some embodiments, the additive component can include a carbonate. Thecarbonate may include a propylene carbonate.

In some embodiments, the additive component can include at least one ofa glycol ether, a glycol ether acetate, a tetramethyl urea, ann-methylpyrrolidone, an acetonitrile, a tetrahydrofuran (THF), adimethyl formamide (DMF), an N-methyl formamide (NMF), a dimethylsulfoxide (DMSO), a thionyl chloride, a sulfuryl chloride, a1,2-diaminoethane, a propane-1,3-diamine, a butane-1,4-diamine, apentane-1,5-diamine, a hexane-1,6-diamine, a 1,2-diaminopropane, adiphenylethylenediamine, a diaminocyclohexane, an o-xylylenediamine, ano-phenylenediamine, an m-phenylenediamine, a hexane, a decane, ateradecane, a styrene, a 1-vinyl-2-pyrolidone, a toluene, a pyridine,and a triethyl phosphate.

In some embodiments, the conductive ink has a viscosity at about 25° C.in a range from about 5,000 centipoise to about 11,000 centipoise.

In some embodiments, the nickel component is in a range from about 50 wt% to about 60 wt %. In some embodiments, the nickel component is in arange from about 35 wt % to about 65 wt %.

In some embodiments, the carbon component is in a range from about 0.5wt % to about 2.5 wt %. In some embodiments, the carbon component isless than about 10 wt %.

In some embodiments, the polycarboxylic acid component is in a rangefrom about 5 wt % to about 15 wt %.

In some embodiments, the polyol component is in a range from about 25 wt% to about 40 wt %. In some embodiments, the polyol component is in arange from about 15 wt % to about 60 wt %.

In some embodiments, the additive component is less than about 10%.

In some embodiments, a printed conductive nickel film can be fabricatedusing a nickel ink prepared according to a method described herein. Insome embodiments, the conductive nickel film can have a sheet resistanceof less than about 1.5 Ohms per square per mil (Ohms/sq/mil). In someembodiments, the conductive nickel film can have a sheet resistance ofless than about 1.0 Ohms/sq/mil. In some embodiments, the conductivenickel film can have a surface roughness of less than about 10. In someembodiments, the conductive nickel film can have polar liquid phobicity.In some embodiments, the conductive nickel film can have hydrophobicity.In some embodiments, the conductive nickel film can have an adhesionvalue of less than 3. In some embodiments, the conductive nickel filmcan have a viscosity of about 9,000 centipoise (cP) at a temperature ofabout 25° C.

In some embodiments, a conductive ink can include a nickel component, apolycarboxylic acid component, and a polyol component. In someembodiments, the polycarboxylic acid component and the polyol componentcan be reactable to form a polyester component.

In some embodiments, the nickel component can include nickel flakes. Insome embodiments, the polycarboxylic acid component can include glutaricacid and the polyol component can include ethylene glycol.

In some embodiments, a nickel film printed using the conductive ink canhave a sheet resistance of about 0.4 Ohms per square per 0.001 inch(mil) (together, Ohms/sq/mil) to about 0.5 Ohms/sq/mil.

In some embodiments, the conductive ink can include a polar liquidphobicity additive. The polar liquid phobicity additive may includedimer diamine.

In some embodiments, the conductive ink can include a printabilityenhancing additive. The printability enhancing additive may includestyrene. In some embodiments, the printability enhancing additive caninclude a peroxide. The peroxide can include at least one of a benzoylperoxide, a 2-butanol peroxide, a 2,4-chlorobenzoyl peroxide, and alauryl peroxide.

In some embodiments, the polycarboxylic acid component can include atleast one of a maleic acid, a fumaric acid, a glutaconic acid, atraumatic acid and a muconic acid. In some embodiments, the polyolcomponent can include an unsaturated diol. In some embodiments, thepolyester component can include an unsaturated polyester component. Insome embodiments, the conductive ink can include graphene flakes.

In some embodiments, a method of fabricating a conductive ink caninclude dispersing a nickel component in a polyol component, anddispersing a polycarboxylic acid component in the polyol component. Insome embodiments, the polycarboxylic acid component and the polyolcomponent can be reactable to form a polyester component.

In some embodiments, the polycarboxylic acid component can includeglutaric acid and the polyol component can include ethylene glycol.

In some embodiments, the nickel component can include nickel flakes.

In some embodiments, the method of fabricating the conductive ink caninclude removing nickel oxide from one or more surfaces of the nickelflakes. Removing the nickel oxide can include heating the nickel flakesin the presence of the polycarboxylic acid component. In someembodiments, heating can include heating the nickel flakes and thepolycarboxylic acid component to a temperature of about 80° C. to about120° C.

In some embodiments, the method of fabricating the conductive ink caninclude adding a polar liquid phobicity additive. The polar liquidphobicity additive may include dimer diamine.

In some embodiments, the method of fabricating the conductive ink caninclude mixing the nickel component with mixing media for reducing anickel component particle size, where the mixing media can includebeads. In some embodiments, the beads can include zirconia beads havinga diameter of about 0.3 millimeters (mm) to about 10 mm. In someembodiments, the method of fabricating the conductive ink can includemixing the nickel component with the zirconia beads for a duration ofbetween about 1 hour and about 2 days. In some embodiments, the mixturecomprising the nickel flakes and zirconia beads having a diameter ofabout 0.3 mm to about 10 mm, including about 1 mm to about 10 mm, about1 mm to about 5 mm, and about 5 mm to about 10 mm can be rotated for atleast about 1 hour (hr) to about 3 days, including about 1 hour to about2 days, about 1 hr to about 1 day, about 1 hr to about 12 hr, about 12hr to about 1 day, and about 1 day to about 2 days.

In some embodiments, the method can include mixing the mixing media andthe nickel component in a jar mill. The jar mill may have a diameter ofabout 3 inches to about 15 inches. In some embodiments, the method caninclude rotating the jar mill at a rotation speed of about 50revolutions per minute (RPM) to about 200 RPM.

For purposes of summarizing the invention and the advantages achievedover the prior art, certain objects and advantages are described herein.Of course, it is to be understood that not necessarily all such objectsor advantages need to be achieved in accordance with any particularembodiment. Thus, for example, those skilled in the art will recognizethat the invention may be embodied or carried out in a manner that canachieve or optimize one advantage or a group of advantages withoutnecessarily achieving other objects or advantages.

All of these embodiments are intended to be within the scope of theinvention herein disclosed. These and other embodiments will becomereadily apparent to those skilled in the art from the following detaileddescription having reference to the attached figures, the invention notbeing limited to any particular disclosed embodiment(s).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view of a nickel ink printed in a design usable todetermine a sheet resistance of the printed nickel ink by van der Pauwmeasurement.

FIG. 1B is a plan view of a nickel ink printed in a design afterperformance of a tape test for measuring adhesion.

DETAILED DESCRIPTION

Although certain embodiments and examples are described below, those ofskill in the art will appreciate that the invention extends beyond thespecifically disclosed embodiments and/or uses and obvious modificationsand equivalents thereof. Thus, it is intended that the scope of theinvention herein disclosed should not be limited by any particularembodiments described below.

In some embodiments, a conductive ink comprises a nickel flake, whichhas a relatively low cost (e.g., about $0.01 per gram to about $0.05 pergram). In some embodiments, the ink, and/or the film printed using theink, has good adherence to many types of substrates and/or can becompletely cured at about 130° C. to about 140° C. and highertemperatures for a duration of about 3 minutes (min) to about 10 min.The ink's viscosity may be designed for screen printing and may be inthe range of about 5,000 centipoise (cP) to about 11,000 cP at roomtemperature (about 25° C.). In some embodiments, the shelf life of theink is at least about 3 months. In some embodiments, a printed film(e.g., printed from the conductive ink) or coating comprises a nickelcomponent (e.g., nickel flakes), carbon component (e.g., graphene), andpolyester. The printed film may have high conductivity (e.g., sheetresistance of less than about 1.5 Ohm/sq/mil, including less than 0.5Ohm/sq/mil, including about 0.5 Ohm/sq/mil to about 1.5 Ohm/sq/mil). Thecoatings may have a thickness of about 4 microns (μm) to about 40 μm.

The ink may be designed for use in various layers of a printed energystorage device (e.g., as a current collector layer). Embodiments ofexample printed energy storage devices are provided in PCT PatentApplication No. PCT/US2013/064309, filed Oct. 10, 2013, which isincorporated herein by reference in its entirety. See, for example,FIGS. 1, 2, 7 and 8, and pages 22-31 and 33-47 of the PCT application.

In some embodiments, the conductive ink can be used as a conductive inkfor other applications, for example an antistatic coating and/or inradio frequency and electromagnetic shielding coating.

In some embodiments, the conductive ink can facilitate an efficientportable energy storage system, which can help to enhance the use ofstored power, reducing overall energy consumption. The conductive inkmay be recyclable, for example because the components can be separated.In some embodiments, the conductive ink comprises components which arenon-toxic such that, for example, the conductive ink can be disposed ina landfill without special procedures without adversely impacting theenvironment.

Example Composition and its Preparation Procedure

One embodiment of a composition of a conductive ink comprising nickelflake is presented in Table 1, along with the corresponding printingconditions in Table 2, and the parameters of the corresponding printedfilm are presented in Table 3.

The example ink composition presented in Table 1 was chosen by theparameters of the film printed from it (Table 3 shows the parameters).Adhesion of films to substrates was satisfactory on the majority ofinks, so a key criterion for the ink composition presented in Table 1was a balance between conductivity (described herein in terms of sheetresistance, Ohm/sq/mil) and smoothness of the printed film.

TABLE 1 Ink Composition Ink Poly- Compo- carboxylic Other nent NickelCarbon Acid Polyol additives Variety Flakes, 1 Graphene Glutaric acidEthylene N/A micron thick, flakes, 5 glycol 5-20 microns microns in indiameter diameter Weight 55.6 1.4 10.2 32.8 None Percent, wt %

In some embodiments, the ink composition of Table 1 can be preparedusing the following process: Graphene flakes are mixed with ethyleneglycol and sonicated for 30 min at 90° C. to disperse the grapheneflakes in the ethylene glycol. Nickel flakes are added to the mixture ofgraphene flakes and ethylene glycol, stirred with a stirrer (e.g., usinga Lab Egg) for 10 min at 100° C. and sonicated for 30 min at 90° C. todisperse the Ni flakes in the ethylene glycol and with the grapheneflakes. The graphene may be between nickel flakes (e.g.,Ni-graphene-Ni), which can increase inter-particle contact and improveconductivity. The graphene may be between nickel flakes (e.g.,Ni-graphene-Ni), which can reduce agglomeration. The mixture of grapheneflakes, Ni flakes, and ethylene glycol is then heated to 100° C. andglutaric acid is added. The mixture of graphene flakes, Ni flakes,ethylene glycol, and glutaric acid is stirred (e.g., using a Lab Egg)for 30 min and cooled down.

In some embodiments, components of the ink may be combined at the sametime (e.g., simultaneously or substantially simultaneously). Forexample, the graphene flakes, ethylene glycol, nickel flakes, and theglutaric acid may be combined at the same time to form a mixture. Insome embodiments, the mixture can be heated after dispersion off all ofthe components. In some embodiments, the mixture can be heated to atemperature of about 80° C. to about 120° C. (e.g., about 100° C.), forexample to inhibit or prevent formation of polymer before curing.

In some embodiments, a polyester may be formed upon mixing an alcoholand an acid. For example, a polyester may be formed upon heating of amixture comprising an alcohol component and an acid component. In someembodiments, an ink mixture comprises a polyester component that isformed in situ (e.g., within or during formation of the ink, includingfor example during curing of the conductive ink to form a conductivefilm). In situ formation of the polyester component may provide acontrollable process for the formation of the polyester component, maybetter disperse in the ink, and/or may increase interaction with nickelcomponents, carbon components, and/or additives. In the ink, the acidcan etch non-conductive materials such as nickel oxide from nickelcomponents, which can increase conductivity since more conductive nickelis exposed. Once the acid is converted to polymer during curing, oxideis less likely to form on the nickel components, for example due tobeing at least partially surrounded by polymer. A polymer in an ink caninhibit printing or cause poor printability, and forming a polymerduring curing after printing can advantageously avoid any impact ofpolymer in ink during printing.

In some embodiments, a polyester component can be formed external to theink (e.g., made separately, purchased, etc.) and added directly. Forexample, fabricating a conductive nickel ink may include adding apolyester component a mixture instead of or in addition to forming thepolyester component in situ. Adding a pre-formed polyester component tothe ink may simplify the fabrication process by incorporating a knownquantity and variety (e.g., average molecular weight, a polymer size,monomers and/or repeating units, etc.) of the polyester component.Polymer size may be adjusted, for example, to adjust printability.

The ink composition of Table 1 may be printed using a screen printingtechnique. An example of possible screen printing parameters arepresented in Table 2.

TABLE 2 Printing Conditions Viscosity at Curing Curing time, 25° C., cPMesh type Mesh size temperature, ° C. min 9,000 Polyester 110 138 10

The parameters of the example printed film are presented in Table 3. Thethickness measurement was conducted using an electronic thickness gauge.Sheet resistance was measured using the van der Pauw technique. Forexample, commonly practiced methods associated with the van der Pauwtechniques may be applied to one or more printed conductive filmsdescribed herein to evaluate a sheet resistance of the printedconductive film. For example, the ink printed in a special design, asshown in FIG. 1A, can be used when applying the van der Pauw techniqueto determine a sheet resistance.

To evaluate the adhesiveness of a printed nickel conductive film to asubstrate, a cross-cut test may be used, including for example an ISO2409 Cross Cut Test. A cross-cut test may be used to determine whether aprinted film exhibits adequate adhesion to a substrate. In someembodiments, a cross-cut test can allow categorizing an adhesiveness ofthe printed film according to predetermined levels of adhesiveness.

In a cross-cut test, a lattice pattern having a set of six cuts in eachof two directions may be made in a printed conductive nickel film. Thesix cuts in each set may be parallel or substantially parallel to oneanother. The first set of six cuts may be perpendicular or substantiallyperpendicular to the second set of six cuts. The cutting may beperformed with a single blade knife and/or a multi-blade cutting tool.For example, a multi-blade cutting tool may have blades spaced about 1millimeter or about 2 millimeters apart. Spacing of the cuts in each setof cuts may depend on a thickness of the printed conductive film and/ora hardness of the substrate on which the film is printed. For example,cuts spaced about 1 millimeter apart may be applied to a printed filmhaving a thickness of less than about 60 microns and where the film isprinted on a hard substrate. For example, cuts spaced about 2millimeters apart may be applied to a printed film having a thickness ofabout 60 microns to about 120 microns and where the film is printed on asoft substrate. In some embodiments, cuts spaced about 3 millimetersapart can be applied to a printed film having a thickness of about 120microns to about 250 microns and where the film is printed on either ahard or soft substrate. The cuts may penetrate through to the substrateon which the film is printed.

Pressure sensitive tape (e.g., an Elcometer ISO 2409 Adhesive Tape) canbe applied over the cuts in the printed film and then pulled off.Adhesiveness of the printed film may be categorized according topredetermined levels of adhesiveness by comparing the appearance of theprinted film after removing the pressure sensitive tape to descriptionproviding standards for each of the levels. The ISO 2409 Cross-cut testmay allow categorizing adhesiveness of a printed film based on sixpredetermined levels, for example levels 0 through 5, level 0corresponding to a high level of adhesiveness and level 5 correspondinga low level of adhesiveness. For example, level 0 may be appropriate ifthe printed film shows no detachment from the substrate after removal ofthe pressure sensitive tape. A level 1 may be appropriate if less thanabout 5% of a surface area (e.g., a percentage of a surface area overwhich the pressure sensitive film was applied) of the printed filmdetached from the substrate, level 2 if between about 5% to about 15% ofthe surface area detached, level 3 if between about 15% to about 35% ofthe surface area detached, and level 4 if between about 35% to about 65%of the surface area detached. A level 5 may be appropriate if detachmentof the printed film is more severe than that described in level 4. FIG.1B illustrates an example printed film after a cross-cut adhesion test,in which the film exhibits six vertical and horizontal striations.Although the pattern of FIG. 1B is also a pattern suitable for use withcertain resistance measurements, a printed structure for an adhesiontest may take any suitable pattern (e.g., tall and wide enough for thehorizontal and vertical cuts).

TABLE 3 Printed Film Properties Sheet Resistance, Adhesion SubstrateOhm/sq/mil (0-5 range) Biaxially-oriented polyethylene 0.8 1terephthalate (e.g., Mylar ®)

Table 4 lists three examples of different nickel ink compositions:Nickel Ink 1, Nickel Ink 2, and Nickel Ink 3. Nickel Inks 1, 2, 3 eachinclude a nickel component (in the form of nickel flakes), a carboncomponent (in the form of graphene flakes), a polycarboxylic acidcomponent (in the form of glutaric acid), and a polyol component (in theform of ethylene glycol). Table 6 lists examples of parameters of nickelfilms printed using nickel inks having the compositions of Nickel Inks1, 2 and 3 listed in Table 4.

As described above, Nickel Inks 1, 2, 3 can include other forms of thelisted components. For example, Nickel Inks 1, 2, and/or 3 may include apolyol component and/or a polycarboxylic acid component (e.g., adicarboxylic acid, such as maleic acid). In some embodiments, at least aportion of the polycarboxylic and the polyol can undergo chemicalreaction to form polyester. In some embodiments, a nickel ink caninclude one or more additional components to facilitate providing an inkand/or a film printed using the ink having one or more desirablecharacteristics. Nickel Inks 1, 2, and 3 each include one or moreadditives, the possible effects of which are discussed in further detailbelow. Nickel Inks 1 and 2 includes benzoyl peroxide and styrene. NickelInk 3 does not include benzoyl peroxide or styrene. Nickel Inks 2 and 3include dimer diamine and cyclohexanol. Nickel Ink 1 does not includedimer diamine or cyclohexanol. A solvent (e.g., an organic solvent suchas cyclohexanol) can be selected based on a variety of factors,including for example ease of evaporation in an ink curing process.

TABLE 4 Ink Composition Nickel Nickel Nickel Ink Component Ink 1 (wt %)Ink 2 (wt %) Ink 3 (wt %) Nickel 54.8 53.1 63 Nickel Flakes Carbon 1.41.3 1.6 Graphene Flakes, ~5 μm in diameter Polycarboxylic Acid 6.2 6.07.7 Glutaric Acid Polyol 19.9 19.3 24.7 Ethylene glycol Benzoyl Peroxide8.1 7.8 — Styrene 9.6 9.3 — Dimer Diamine — 1.9 2.0 Solvent — 1.3 1.0Cyclohexanol

In some embodiments, a nickel ink can include one or more additives tofacilitate providing an ink having improved printability (e.g., aprintability enhancing additive, facilitating printing of an ink havinga desired thickness, and/or smoothness, while providing an ink withoutor substantially without holes). For example, the nickel ink can includeone or more components which can interact (e.g., including for example,a chemical reaction, such as a polymerization reaction) with thepolyester, and/or one or more precursors of the polyester (e.g., thepolycarboxylic acid and/or the polyol) to provide a stronger ink (e.g.,an ink which can better withstand a tensile, twisting, compressive,and/or shear force). In some embodiments, the nickel ink can includestyrene. For example, styrene can interact with the polyester and/or oneor more of the polyester precursors to facilitate providing a strongernickel ink. In some embodiments, the styrene can undergo aco-polymerization reaction with an unsaturated polyester and/or one ormore of the unsaturated polyester precursors (e.g., a dicarboxylic acid,such as maleic acid, fumaric acid, glutaconic acid, traumatic acidand/or muconic acid; and/or an unsaturated diol). In some embodiments,the nickel ink can include an initiator to facilitate interactionbetween the styrene and the unsaturated polyester and/or one or more ofthe unsaturated polyester precursors (e.g., facilitate aco-polymerization reaction). For example, the nickel ink can includebenzoyl peroxide for facilitating the co-polymerization reaction betweenstyrene and the unsaturated polyester and/or one or more of theunsaturated polyester precursors (e.g., benzoyl peroxide as an activatorfor the co-polymerization reaction). Other suitable activators may alsobe used, including for example, other suitable peroxides. Referringagain to Table 4, Nickel Inks 1 and 2 include benzoyl peroxide andstyrene.

In some embodiments, a nickel ink can include one or more additionalcomponents to facilitate providing an ink and/or a film having improvedpolar liquid phobicity, such as improved hydrophobicity (e.g., a polarliquid phobicity additive, for facilitating reduced absorption of waterand/or other polar liquids by the ink and/or a film printed using theink). The one or more additional components for facilitating an inkand/or a film having improved polar liquid phobicity can include apolymer and/or a polymer precursor, either or both of which can includea long hydrophobic chain (e.g., a long hydrocarbon chain). For example,the nickel ink can include dimer diamine to facilitate providing anickel ink and/or film having improved polar liquid phobicity. In someembodiments, the dimer diamine can undergo a polymerization reactionwith a polyester and/or one or more polyester precursors of the nickelink. Referring again to Table 4, Nickel Inks 2 and 3 include dimerdiamine.

In some embodiments, a nickel ink and/or film having polar liquidphobicity can demonstrate minimal, or no or substantially no absorptionof ionic liquids used in various parts of an energy storage device.Energy storage devices may include one or more liquid components (e.g.,an aqueous electrolyte, and/or one or more other components which caninclude an ionic liquid and/or any other liquid) which can be absorbedby the nickel film, adversely affecting an electrical performance of thenickel film, such as reducing an electrical conductivity of the nickelfilm. For example, an electrode and/or a separator of an energy storagedevice can include one or more ionic liquids. Embodiments of exampleenergy storage devices which include an electrode and/or a separatorcomprising ionic liquid are provided in PCT Patent Application No.PCT/US2013/064309, filed Oct. 10, 2013, which is incorporated herein byreference in its entirety. See, for example, pages 24-26, 28-30, and43-48 of the PCT application.

In some embodiments, the Nickel Inks 1, 2, and 3 of Table 4 can beprepared using the following process: glutaric acid and ethylene glycolare mixed until the glutaric acid is dissolved or substantiallydissolved in the ethylene glycol. Nickel flakes and graphene flakes canthen be added and mixed. For example, mixing and/or dispersing of thenickel flakes and graphene flakes within the mixture can be done byusing a stirrer (e.g., using a Lab Egg) to stir the mixture for about 10min at about 100° C., and/or by sonicating the mixture for about 30 minat about 90° C. As described herein, the graphene may be between nickelflakes (e.g., Ni-graphene-Ni), which can increase inter-particlecontact, improve conductivity, and/or reduce agglomeration.

For nickel inks including one or more components to facilitate providingan ink having improved printability, the one or more components can beadded to the mixture comprising the nickel and graphene flakes. Forexample, for Nickel Inks 1 and 2 of Table 4, styrene and benzoylperoxide can be added to and/or mixed with the mixture comprising thenickel flakes and the graphene flakes.

In some embodiments, a nickel ink manufacturing procedure can include aprocess for reducing a nickel component particle size. For example,nickel flakes can undergo a process to reduce a size of the nickelflakes. In some embodiments, the nickel flakes and/or one or more othernickel ink components can undergo a mixing process using mixing media(e.g., in a jar mill, as described herein), which can break apart thenickel flakes and reduce a size of the nickel flakes. Other methods ofreducing a nickel flake size may also be suitable. Other mixingapparatuses and/or mixing media may also be suitable to facilitatereducing the size of nickel flakes. For example a roller mill may alsobe suitable for mixing nickel flakes with mixing media. The nickelflakes can undergo the process for reducing a nickel flake size beforeand/or after combining the nickel flakes with one or more othercomponents of the nickel ink (e.g., before and/or after combination ofnickel flakes and graphene flakes with glutaric acid and ethyleneglycol, such as mixing only nickel flakes with the mixing media). Insome embodiments, nickel flake size may be reduced prior to adding thenickel flakes to a mixture. Performing a nickel flake size reductionprocess with the nickel flakes in a mixture (e.g., including one or moreother nickel ink components) using a jar mill may advantageouslyfacilitate reduced costs of fabricating a nickel film and/or nickel inkhaving increased smoothness and/or printability. In some embodiments, ajar mill can facilitate improved disintegration of agglomerated mixingmedia and/or agglomerated particles of the mixture being processed,and/or improve wetting of particles of the mixture being process. Mixinga mixture comprising the nickel flakes and one or more other nickel inkcomponents with a mixing media may facilitate further dispersion of thenickel flakes within the mixture.

Nickel flakes having a smaller size can contribute to a smoother nickelink and/or film (e.g., reduced roughness), and/or improve printabilityof the nickel ink (e.g., facilitate printing of thinner films). Smoothernickel ink and/or film may be desirable for various applications. Forexample, nickel ink and/or nickel film having reduced roughness may bedesirable for electromagnetic shield applications, and/or use of nickelfilm on circuit boards of various electronic applications (e.g., as acheaper alternative for other conductive materials, such as silver (Ag)containing materials, used on circuit boards).

In some embodiments, the nickel ink mixture can be mixed with a mixingmedia (e.g., beads, such as zirconia beads) in a jar mill. The mixingmedia can be removed from the mixture after completion of the mixingprocess, for example after nickel flakes of a desired size (e.g.,average size, size range, etc.) is obtained. In some embodiments, a sizeof the mixing media can be selected to facilitate providing nickelflakes of a desired size. For example, a size of the zirconia beads(e.g., a diameter of spherical or substantially spherical beads) can beselected to provide nickel flakes of a desired diameter and/or a desiredlongest dimension. In some embodiments, a size of the nickel flakes canbe directly proportional to a dimension of the mixing media (e.g.,smaller sized mixing media can facilitate providing smaller nickelflakes). In some embodiments, zirconia beads having a diameter of about5 millimeters (mm) to about 10 mm can provide nickel flakes having adiameter and/or longest dimension of about 10 microns (μm). Zirconiabeads smaller than about 5 mm may provide smaller nickel flakes (e.g.,nickel flakes having a diameter and/or longest dimension less than about5 mm, such as about 0.3 mm to about 5 mm).

Reduced nickel flake particle size can facilitate increased smoothness(e.g., decreased roughness) of the nickel ink and/or nickel film printedusing the nickel ink. Table 5 provides examples of roughnessmeasurements of nickel films printed using the composition of Nickel Ink1 of Table 4 where the nickel ink used for printing the films isprepared using mixing media of various sizes. For example, Table 5 showsthat a roughness of the printed film increases with increase in size ofmixing media used. Roughness measurements can be performed according tovarious methods know to those skilled in the art, including for example,a contact profilometer (e.g., a profilometer which contacts a nickelfilm surface with a stylus to measure a roughness of the nickel filmsurface) and/or non-contact profilometer (e.g., an opticalprofilometer).

TABLE 5 Examples of printed nickel film roughness and size of mixingmedia used in preparation of the corresponding nickel ink Mixing MediaSize (Diameter), Range of Roughness, mm μm  5-10  5-10 2-5 3-7

Nickel flakes, and/or one or more other components of the nickel ink,and zirconia beads can be rotated in a jar mill at a rotational speedfor a duration of time to provide nickel flakes of a desired size.Various rotational speeds may be suitable. Rotational speed of a jarmill can be depend on a variety of parameters, including for example, ageometry of the jar mill (e.g., size and/or shape) and/or a viscosity ofthe mixture being processed.

A rate at which nickel particles are broken apart (e.g., a rate ofgrinding) inside a jar mill can depend on the speed at which the millcylinder of the jar mill is rotating. The mixture being processed and/orthe mixing media within the jar mill moving in a cascade-like motion(e.g., cascading, or moving in a motion like that of a waterfall) mayindicate that the rotating speed is providing a desired rate ofgrinding. In some embodiments, cascading can involve the mixture and/orthe mixing media within the jar mill cylinder breaking away from aninterior wall of the mill cylinder processing cavity at an angle ofabout 45 degrees to about 60 degrees relative to a horizontal referenceline. Cascading of the mixture and/or the mixing media within the millcylinder can facilitate falling and/or rolling of the mixing mediaand/or the mixture from the outer edges of the mill cylinder processingcavity in a coherent, mobile mass, for example creating an impact thatfractures particles of the mixture (e.g., reducing a particle size ofnickel flakes in the mixture). In some embodiments, secondary actionswithin the mill cylinder processing cavity involving the mixing mediaand/or the mixture which are not at the outer edges cataracting downwardcan contribute to further breaking apart of particles of the mixture,for example through rotational action of the mixing media and/or themixture, and/or rubbing action between one or more interior surfaces ofthe mill cylinder processing cavity, the mixing media and/or themixture. In some embodiments, cascading of the mixture and/or the mixingmedia, and secondary actions involving the mill cylinder, mixing media,and/or the mixture, can facilitate significantly improved reduction inparticle size of the mixture, improved dispersion of components of themixture, for example due to increased shear forces from spinning of themixing media. In some embodiments, cascading of the mixture and/or themixing media, and secondary actions involving the mill cylinder, mixingmedia, and/or the mixture, can facilitate increased wetting of particlesof the mixture during a wet process.

In some embodiments, high rotational speeds of a mill cylinder canresult in centrifuging of the mixture and/or the mixing media. Forexample, centrifuging of the mixture and/or the mixing media may resultin separation of mixing media from particles of the mixture, for examplecontributing to un-ground or substantially un-ground material, unevendisintegration of particles of the mixture and/or uneven dispersion ofparticles within the mixture.

In some embodiments, slow rotational speeds of a mill cylinder cancontribute to slipping of the mixing media and/or the mixture particleswithin the jar mill cylinder processing cavity, such as due to themixing media and/or the mixture being processed becoming static relativeto the walls of the rotating mill cylinder. Slipping of the mixing mediaand/or the mixture within a jar mill processing cavity can lead toundesirable wear of the jar mill and/or the mixing media, such asgrooving of the interior of mill cylinder processing cavity walls and/orflattening of the mixing media. In some embodiments, slipping of themixing media can occur if the jar mill is filled with insufficientquantity of mixture and/or mixing media. In some embodiments, slippingcan occur due to low viscosity of the mixture that is being processed.

In some embodiments, lifter bars can be attached (e.g., welded and/or orbolted) to an interior surface of the mill cylinder processing cavityfor reducing slippage. For example, lifter bars may be used when acombined volume of the mixture and the mixing media is below about 45percent of the volume of the mill cylinder processing cavity. In someembodiments, use of lifter bars may be ineffective in reducing and/orpreventing slipping of the mixing media and/or the mixture within themill cylinder if a combined volume of the mixing media and mixture istoo low, such as below about 33 percent of the volume of the millcylinder processing cavity.

A critical rotational speed can be a speed at which an outermost layerof a mixture begins to centrifuge against an interior wall of the millcylinder processing cavity. Critical rotational speed N_(c) of a millcylinder for processing a wet mixture, for example expressed inrevolutions per minute (RPM), can be calculated using the followingequation: N_(c)=54.2/(√R)=76.6/√D), where R is the interior radius ofthe mill cylinder processing cavity, and D is the interior diameter ofthe mill cylinder processing cavity (e.g., R and D may be expressed infeet). Critical rotational speed for processing a dry mixture can beestimated by increasing the N_(c) value calculated above by about 2 RPMto about 5 RPM. A critical rotational speed may be independent of mixingmedia shape and/or density.

In some embodiments, the rotational speed of a mill cylinder can beabout 35 percent to about 115 percent of the critical rotational speedN_(c), including about 60 percent to about 65 percent of critical speed(Nc). In some embodiments, a jar mill can be rotated at varying speedsto facilitate optimized particle size reduction. For example, lowerrates of rotation may be used for wet processing and/or dry processingof soft materials, such as compared to the rates of rotation used in wetprocessing of ceramic frits and glazes.

In some embodiments, higher rotational, such as speeds at or nearcritical speeds, can be used in manufacturing of metallic powders (e.g.,bronze and aluminum powders). For example, such high speeds of rotationmay facilitate flaking of the metallic powders due to powerful impactimparted upon metallic particles by the mixing media.

In some embodiments, a jar mill having a cylinder with a diameter ofabout 3 inches to about 15 inches can be used at rotational speedsbetween about 50 RPM and about 200 RPM to provide nickel flakes havingdesired particle sizes. For example, a rotational speed of about 80 RPMto about 150 RPM, about 100 RPM to about 120 RPM, can be used. Asdescribed herein, in some embodiments, the rotational speed of the jarmill may vary during the nickel flake particle size reduction process.

In some embodiments, optimizing a process for nickel particle sizereduction can be comprise using mixing media having a reducing size.Smaller mixing media can facilitate increased contact per millrevolution and/or reduce a distance across which shear force may act,for example providing increased uniformity in nickel particle sizeand/or facilitating increased reduction of particle size. Larger mixingmedia can provide undesirably high impact energy upon particles of themixture being processed and/or may generate heat in the jar mill if thisincreased energy is not efficiently consumed and/or dissipated. In someembodiments, larger mixing media can be useful to provide increasedimpact energy for breaking apart larger and/or or tougher particles in amixture, and/or for processing a thixotropic wet mixtures.

In some embodiments, optimizing a viscosity of the mixture processed bythe jar mill (e.g., depending on a particle size and/or a density of themixing media and/or the mixture) can facilitate desired grinding of themixture, while reducing wear of the mixing media (e.g., while keepingwear of the mixing media to a rate of about 20 percent per year). Insome embodiments, viscosity of mixtures processed using high densitymixing media can be higher than that processed using porcelain and/orflint mixing media, for example by about 25 percent, such as due togreater impact energy imparted upon the mixture by the high densitymixing media.

In some embodiments, a mixture being processed having high viscosity mayimpede movement of mixing media within the mill, for examplecontributing to reduced grinding action. For example, excessively highviscosity may contribute to increased agglomeration of the mixing mediasuch that the mixing media rotates together in a mass within the mill,significantly impeding grinding action.

In some embodiments, increased viscosity can be desirable, such as whenoperating a larger mill cylinder (e.g., mill cylinder having a largerdiameter). A heavier-bodied cushion may be used to prevent wear due toincreased weight of the mixing media. In some embodiments, operating alarger mill cylinder may involve use of increased horsepower forrotating the larger mill cylinder, the increased horse power beingtransformed into heat, which may lower the viscosity of the mixture(e.g., which may be accounted for to obtain optimized mixtureviscosity).

Viscosity of the mixture being processed can be measured using varioustechniques known by one skilled in the art. For example, a KrebsStormer® Viscometer (e.g., with the 52.2 mm seep flat paddle, Krebs'modification, commercially available from Thomas Scientific, of NewJersey), may be used for measuring viscosity. For example, a viscosityof about 600 centipoise (cP) to about 1,100 cP (e.g., about 70 KrebsUnits (KU) to about 90 KU) can be used for a process using mixing mediacomprising flint pebbles and/or porcelain balls. For example, aviscosity over about 2,200 cP (e.g., over about 110 KU) can be used fora process using mixing media comprising high-density mixing media.

A desired combined volume occupied by a mixture and mixing media forfacilitating desired particle size reduction in a jar mill can depend ona material of the mixing media. In some embodiments, it may be desirablefor a mixture and mixing media to fill about 45 percent to about 55percent of the total interior processing cavity volume of the millcylinder, including from about 45 percent to about 50 percent. In someembodiments, a jar mill cylinder having two low a volume filled by amixture and mixing media may contribute to increased wear on the mixingmedia and/or the interior surfaces of the mill cylinder processingcavity (e.g., due to slipping of the mixing media on one or moreinterior surfaces of the mill cylinder processing cavity). In someembodiments, a combined volume occupied by a mixture processed by ahigh-density ceramic mixing media and the mixing media itself, can beabout 45 to about 50 percent of an interior processing cavity volume. Insome embodiments, a combined volume occupied by a mixture processed bymixing media comprising flint pebbles and/or standard porcelain, and themixing media itself, can be about 50 percent to about 55 percent of aninterior processing cavity volume of a mill cylinder. For example, a wetprocessing porcelain enamel frit, about 50 percent to about 55 percentof an interior volume of a processing cavity can be filled, for examplewhen using either standard and/or high-density mixing media. The fritcharge (slip), expressed in pounds, may be equal to about three to abouttimes four the total volume of the mill, expressed in gallons. Ifstandard porcelain is used, the ratio of frit charge to volume may beabout 3 to about 1. If high density alumina media is used, the ratio offrit charge to volume may be between about 3.5 to 1 and about 4.5 to 1.When steel balls are used, 33 percent and 45 to 50 percent ball chargesmay be used, depending upon the desired mill output. With 33 percentball charges, lifter bars are recommended.

In some embodiments, for grinding of dry mixtures, an interiorprocessing cavity of a jar mill cylinder filled to about 25 percent byvolume by the mixture and about 25 percent by volume by the mixing media(e.g., half of the occupied volume in the mill is filled by the mixtureand half is by the mixing media), may facilitate improved efficiency incontact between the mixture and the mixing media and/or one or moreinterior surfaces of the processing cavity.

In some embodiments, a volume occupied by mixing media and the mixturebeing processed within a processing cavity of a jar mill can bemaintained at least about 25 percent total mill processing cavityvolume, for example by initially filling the mill processing cavity to30 percent to about 40 percent of its total volume. In some embodiments,a mixture an apparent volume of approximately 60 percent solid and 40percent voids, for example providing a mill processing cavity about 50percent full would have a capacity in the voids of 20 percent of thetotal mill volume.

In some embodiments, a duration of the mixing process can depend on anamount of mixture processed by the jar mill. For example, a longerduration of the mixing process may be used for processing an increasedamount of mixture, and a shorter duration of the mixing process may beused for processing a decreased amount of mixture.

Increased duration of rotation may facilitate increased reduction innickel flake size, facilitating nickel flakes having smaller dimensions.In some embodiments, the mixture comprising the nickel flakes andzirconia beads having a diameter of about 0.3 mm to about 10 mm,including about 1 mm to about 10 mm, about 1 mm to about 5 mm, and about5 mm to about 10 mm can be rotated for at least about 1 hour (hr) toabout 3 days, including about 1 hour to about 2 days, about 1 hr toabout 1 day, about 1 hr to about 12 hr, about 12 hr to about 1 day, andabout 1 day to about 2 days. For example, mixing media comprisingzirconia beads having a 0.3 mm to about 5 mm can be rotated for aduration of up to about 2 days to provide nickel flakes having adiameter and/or longest dimension of about 10 μm. The longer theduration of rotation, the smaller nickel flake size may be achievable. Aduration of rotation for achieving desired nickel particle size maydecrease with a decreased viscosity of the mixture comprising the nickelflakes. In some embodiments, a viscosity of the mixture that isprocessed can be decreased by adding one or more solvents to themixture. For example, a solvent comprising ethanol may be added to themixture comprising the nickel flakes to decrease a viscosity of themixture. The reduced viscosity mixture can be processed to reduce thesize of nickel flakes therein. The solvent may subsequently be removedafter the nickel flake size reduction process, such as by evaporation.For example, excess solvent may be evaporated until the nickel ink has adesired viscosity (e.g., solvent can be evaporated such that the nickelink achieves a viscosity of about 9,000 cP). For another example, aviscosity of the mixture can be decreased by increasing a temperature ofthe mixture during the nickel flake size reduction process, such asmaintaining the mixture at an elevated temperature during the process.In some embodiments, duration of rotation can depend on various otherfactors, including for example, a concentration of dispersants in themixture and/or an initial particle size of the nickel flakes. Usingsmaller mixing media may reduce the size of the nickel flakes in ashorter duration, but may be more expensive, difficult to separate aftersize reduction, etc.

In some embodiments, a nickel component (e.g., nickel flakes) mayundergo a process to reduce a size to larger than discussed above (e.g.,greater than about 10 μm), or may not undergo a process to reduce a sizeof the flakes (e.g., providing a nickel film having increasedroughness). In some embodiments, nickel ink and/or nickel film havingincreased roughness can be desirable. For example, use of nickel filmhaving increased roughness may be advantageous in one or moreapplications to conduct current between electrically conductiveterminals, such as in applications for energy storage devices (e.g., aspart of current collectors of batteries, supercapacitors, and/orultracapacitors, including for example electric double-layer capacitors(EDLC)). For example, nickel flakes for use in one or more applicationsin which conduction of current between terminals (e.g., two electroniccomponents of an electronic device) may be desired can have nickelflakes which have a diameter and/or a longest dimension of about 10 μmto about 15 μm, including about 10 μm to about 12 μm. Without beinglimited by any particular theory or mode of operation, larger nickelflakes in a nickel ink mixture may facilitate improved currentconduction due to increased continuous surface area between the layercomprising the nickel component and an adjacent layer where currentconduction can occur, improved interlayer adhesion between the layercomprising the nickel component and the adjacent layer, and/or provideincreased contact between conductive components of the nickel film(e.g., amongst the nickel component, such as nickel flakes, and/orcarbon component, such as graphene, and/or between the nickel componentand the carbon component) to facilitate current conduction.

In some embodiments, a mixture comprising a nickel component (e.g.,nickel flakes), and a polycarboxylic acid component (e.g., glutaricacid) can be heated for duration of time. Heating the nickel flakes andthe acid can contribute to increased electrical conductivity of a nickelfilm fabricated using the mixture. In some embodiments, heating of thenickel flakes in the presence of the acid component can facilitateremoval of nickel oxide formed on one or more surfaces of the nickelflakes (e.g., due to native oxidation of the nickel flakes), makingavailable increased conductive surface area on the nickel flakes. Theheating process can be performed at various temperatures. For example,the heating process can be performed at a temperature of about 50° C. toabout 150° C., preferably at a temperature of about 80° C. to about 120°C., more preferably at a temperature of about 90° C. to about 110° C.,most preferably at a temperature of about 95° C. to about 105° C. Forexample, the heating process can be performed at a temperature of about100° C. Removing oxide from the nickel flakes when the mixturecomprising the nickel component and the polycarboxylic acid component isat too low a temperature may result in insufficient nickel oxideremoval, for example providing a process with increased duration toachieve desired oxide removal. Increasing duration may result inundesired evaporation of one or more components of the mixture (e.g., asolvent component). Removing oxide from the nickel flakes when themixture comprising the nickel component and the polycarboxylic acidcomponent is at too high a temperature may result in undesiredevaporation of one or more components of the mixture (e.g., a solventcomponent) and/or undesired polymerization between components of themixture (e.g., between the polycarboxylic acid component and a polyolcomponent).

The nickel flakes and the acid can be heated for a duration of time toachieve desired improvement in electrical conductivity of the filmfabricated from the ink. In some embodiments, the heating process can beperformed for a duration of about 15 minutes (min) to about 3 hours(hr), including about 45 min to about 75 min, and including about 50 minto about 70 min. For example, the nickel flakes and acid component canbe heated for a duration of about 1 hr to about 2 hrs, including about 1hr to about 1.5 hrs, for example about 1 hour, at a temperature of about80° C. to about 120° C., for example about 100° C. The duration ofheating can depend on a variety of parameters, including for example atemperature of the heating process, and/or a quantity of the mixturecomprising the nickel flakes and the acid component being heated.

The heating process can be performed before and/or after a process forreducing a particle size of the nickel flakes. In some embodiments,heating of the nickel flakes and the acid component after a process forreducing a nickel flake particle size, in comparison to a similar nickelfilm fabricated without a heating process to remove nickel oxide, canincrease the nickel film conductivity by at least about two times orabout three times. For example, a nickel film printed using an ink(e.g., Nickel Ink 1 of Table 4) that did not undergo a heating processto facilitate etching of nickel oxide on one or more surfaces of thenickel flakes in the ink can have a sheet resistance of about 0.8 Ohmsper square per mil (Ohms/sq/mil) to about 1.0 Ohms/sq/mil, such as about0.9 Ohms/sq/mil. A nickel film printed using an ink having similarcomposition and that has undergone a heating process for removing nickeloxide can have a sheet resistance of about 0.4 Ohms/sq/mil to about 0.5Ohms/sq/mil, such as about 0.45 Ohms/sq/mil.

In some embodiments, one or more components of a nickel ink forfacilitating improved polar liquid phobicity can be added to the nickelink mixture after a heating process (e.g., for removing nickel oxidefrom one or more surfaces of nickel flakes in the nickel ink mixture).In some embodiments, the one or more components for facilitatingimproved polar liquid phobicity can be added to the nickel ink mixturewhile maintaining the nickel ink mixture at a temperature of about 50°C. to about 100° C. In some embodiments, the one or more components forfacilitating improved polar liquid phobicity can be added to the nickelink mixture while stirring the nickel ink mixture. For example, dimerdiamine can be added to the nickel ink mixture while maintaining thenickel ink mixture at a temperature of about 50° C. to about 100° C. andstirring the nickel ink mixture for about 20 minutes (min) to about 40min, such as for about 30 min.

In some embodiments, an organic solvent (e.g., cyclohexanol) can beadded to the nickel ink mixture. In some embodiments, the organicsolvent can be added after addition of other components of the inkmixture. For example, the organic solvent can be added to the inkmixture after addition of dimer diamine for Nickel Ink 3 of Table 4. Insome embodiments, the organic solvent can be added prior to a processfor reducing a nickel flake particle size (e.g., before mixing thenickel ink mixture in a jar mill with mixing media). For example, theorganic solvent can be added after the addition of nickel flakes andgraphene flakes for Nickel Ink 2 of Table 4. In some embodiments, thesolvent can be added at various points in the nickel ink fabricationprocess to change a viscosity of a mixture comprising one or morecomponents of the nickel ink and/or improve printability of the nickelink.

A nickel ink can be printed onto a substrate (e.g., a polyestersubstrate, Mylar®) using one or more processes described herein. One ormore of Nickel Inks 1, 2, and 3 of Table 4 can be printed using screenprinting process, such as through a polyester mesh screen having a meshsize of 110. The printed ink can be cured in a force air oven for aduration of about 10 minutes (min) to about 15 min, at a temperature ofabout 130° C. to about 150° C., including about 135° C. to about 145° C.(e.g., including about 280° F. to about 290° F.).

Examples of sheet resistance (e.g., expressed in ohms per square permil, Ohms/sq/mil), adhesion, polar liquid phobicity, thickness (e.g.,expressed in microns, μm), and range of roughness (e.g., expressed inmicrons, μm, based on nickel films fabricated using a jar mill mixingprocess with mixing beads having a diameter of about 5 millimeters (mm)to about 10 mm) performances of nickel films printed using Nickel Inks1, 2 and 3 of Table 4 are listed in Table 6.

TABLE 6 Printed Film Properties Range of Rough- ness, Sheet Adhesion,Polar Thick- (5-10 mm Resistance, (0-5 Liquid ness, beads) Ohms/sq/milRange) Phobicity μm μm Nickel Ink 1 0.45 ± 0.1  1 No 28-32 5-10 NickelInk 2 0.9 ± 0.1 0 Yes 28-32 5-10 Nickel Ink 3 0.7 ± 0.1 0 Yes 28-32 7-12

One or more methods of measuring performance of nickel films asdescribed herein, for example with reference to Table 3, can be used formeasuring one or more of the parameters listed in Table 6. For example,adhesiveness of a film to a substrate can be measured on a scale from 0to 5, with 0 being very adhesive and 5 being least adhesive, using anISO 2409 Cross-cut test. The adhesion performances of Table 6 aremeasured for nickel films printed on a polyester substrate surface(e.g., Mylar®). As described herein, sheet resistance of a printednickel film may be measured using the van der Pauw technique. Polarliquid phobicity of the printed nickel films can be measured using oneor more methods known to one skilled in the art. For example, polarliquid phobicity may be assessed by the Sessile Drop Technique (e.g.,measuring a contact angle of a droplet of liquid with a surface of thenickel film, where the droplet of liquid has a known surface energy, anda contact angle of greater than about 90° may indicate polar liquidphobicity). For another example, polar liquid phobicity may be assessedby soaking the nickel film in a polar liquid for a duration (e.g., about1 month) and then testing properties such as film hardness or softnessand electrical properties for changes that might impair function. Nickelfilm roughness may be measured using various suitable methods, includingfor example, by using a contact profilometer (e.g., a profilometer whichcontacts a nickel film surface with a stylus to measure a roughness ofthe nickel film surface) and/or non-contact profilometer (e.g., anoptical profilometer).

One or more processes of preparing a nickel ink, including for exampleone or more processes as described with reference to Nickel Inks 1, 2,and 3 of Table 4, can be used for preparing the nickel ink compositionscorresponding to the performance parameters of the Nickel Inks 1, 2, and3 listed in Table 6. For example, the listed average roughness forNickel Inks 1, 2, and 3 in Table 6 can be obtained using a mixingprocess in which nickel flakes are broken into smaller pieces usingzirconia beads as mixing media, where the beads can have a diameter ofabout 5 millimeters (mm) to about 10 mm. For another example, the sheetresistance listed in Table 6 can be obtained using nickel inks whichwere heated during the ink fabrication process for removing at least aportion of nickel oxide from one or more surfaces of nickel flakes inthe ink.

Referring to Table 6, nickel films printed using Nickel Inks 1, 2, and 3of Table 4 can be printed to a similar thickness, which can help withcomparison of properties. The nickel film printed using Nickel Ink 1,which includes the additives styrene and benzoyl peroxide, can havereduced sheet resistance, for example as compared to the nickel filmsprinted using Nickel Inks 2 and 3. However, Nickel Ink 1 does not orsubstantially does not demonstrate polar liquid phobicity. The nickelfilm printed using Nickel Ink 1 also demonstrates reduced adhesionperformance as compared to the nickel films printed using the other twonickel ink compositions, and has a reduced roughness as compared to thenickel film printed using Nickel Ink 3. The nickel film printed usingNickel Ink 2, which includes the additives styrene, benzoyl peroxide,dimer diamine, as well as cyclohexanol as a solvent, can demonstratepolar liquid phobicity, improved adhesion performance (e.g., as comparedto the nickel film printed using Nickel Ink 1), and reduced roughness(e.g., as compared to the nickel film printed using Nickel Ink 3).However, the film printed using Nickel Ink 2 demonstrates increasedsheet resistance. The nickel film printed using Nickel Ink 3 does notinclude the additives styrene and benzoyl peroxide, but includes dimerdiamine, and cyclohexanol as a solvent. The nickel film printed usingNickel Ink 3 can demonstrate polar liquid phobicity (e.g., demonstrateminimal, or no or substantially no absorption of polar liquids),improved adhesion performance (e.g., as compared to the nickel filmprinted using Nickel Ink 1), and increased roughness (e.g., as comparedto the nickel film printed using Nickel Ink 3). The sheet resistanceperformance of the nickel film printed using Nickel Ink 3 is betweenthat of the films printed using Nickel Inks 1 and 3.

In some embodiments, composition of a nickel ink for a printed film canbe selected based on one or more desired characteristics of the printednickel film. For example, a nickel film can be printed using a nickelink composition optimized for sheet resistance performance (e.g., NickelInk 1 of Table 4). Reduced sheet resistance may be desirable in a numberof applications, including applications in which the nickel filmprovides electrical conduction between two or more terminals. In someembodiments, a nickel film can have a composition providing polar liquidphobicity and improved adhesiveness to an underlying substrate (e.g.,Nickel Ink 3 of Table 4). As described herein, polar liquid phobicitycan be advantageous in various applications, including for example inenergy storage devices (e.g., batteries, capacitors, and/orultracapacitors). In some embodiments, a nickel ink can be selected toprovide a nickel film having reduced roughness while also having polarliquid phobicity and/or increased adhesion to a substrate (e.g., NickelInk 2 of Table 4). As described herein, reduced roughness may beadvantageous in a number of applications, including for example forconductive films used in circuit boards.

Example Ink Compositions with Slight Variations of the Components of theExample Ink Composition Presented in Table 1

Listed in the tables below are various other examples of nickel inkcompositions suitable for use in printing nickel films. The tables arelabeled with descriptions indicating a change made to a component of thecorresponding nickel ink composition (e.g., a component particle size, aconcentration of a component, a type of material used for a component,and/or the addition of an additive component), as compared to the nickelink composition listed in Table 1. Examples of measured sheet resistance(e.g., expressed in Ohm/sq/mil), adhesion, and range of roughness (e.g.,expressed in μm) are also provided in a corresponding nickel filmproperties table for each of the nickel films printed using the nickelink compositions having the listed change.

Change of Ni flakes to filamentary Ni powder Ink Poly- Compo- carboxylicOther nent Nickel Carbon Acid Polyol additives Variety FilamentaryGraphene Glutaric acid Ethylene N/A Nickel flakes, 5 glycol powder,microns in 2-10 micron diameter Weight 45.2 0.9 8.2 45.6 Percent, wt %

Printed film properties for change of Ni flakes to filamentary Ni powderSheet Resistance, Adhesion Range of Roughness, Ohm/sq/mil (0-5) μm 1.0 310-25 (holes in the prints)

Change of graphene flake diameter from 5 μm to 25 μm Ink Poly- Compo-carboxylic Other nent Nickel Carbon Acid Polyol additives VarietyFlakes, 1 Graphene Glutaric acid Ethylene N/A micron thick, flakes, 25glycol 5-20 microns microns in in diameter diameter Weight 52.8 1.1 9.636.6 Percent, wt %

Printed film properties for change of graphene flake diameter from 5 μmto 25 μm Sheet Resistance, Adhesion Range of Roughness, Ohm/sq/mil (0-5)μm 1.1 1 7-12

Change of graphene flakes to graphite powder Ink Poly- Compo- carboxylicOther nent Nickel Carbon Acid Polyol additives Variety Flakes, 1Graphite Glutaric Ethylene N/A micron thick, powder acid glycol 5-20microns in diameter Weight 52.8 1.1 9.6 36.6 Percent, wt %

Printed film properties for change of graphene flakes to graphite powderSheet Resistance, Adhesion Range of Roughness, Ohm/sq/mil (0-5) μm 1.9 35-10

Change in concentration of carbon additive from 1.4 wt % to 0 wt % Poly-Ink carboxylic Other Component Nickel Carbon Acid Polyol additivesVariety Flakes, 1 N/A Glutaric Ethylene N/A micron thick, acid glycol5-20 microns in diameter Weight 57.1 0 10.1 32.8 Percent, wt %

Printed film properties for change in concentration of carbon additivefrom 1.4 wt % to 0 wt % Sheet Resistance, Adhesion Range of Roughness,Ohm/sq/mil (0-5) μm 0.9 2 10-25, holes in the print

Change in concentration of carbon additive from 1.4 wt % to 0.6 wt % InkPoly- Compo- carboxylic Other nent Nickel Carbon Acid Polyol additivesVariety Flakes, 1 Graphene Glutaric Ethylene N/A micron thick, flakes, 5acid glycol 5-20 microns microns in in diameter diameter Weight 56.2 0.610.1 33.1 Percent, wt %

Printed film properties for change in concentration of carbon additivefrom 1.4 wt % to 0.6 wt % Sheet Resistance, Adhesion Range of Roughness,Ohm/sq/mil (0-5) μm 0.9 1 10-25 (holes in the print)

Change in concentration of carbon additive from 1.4 wt % to 5.8 wt % InkPoly- Compo- carboxylic Other nent Nickel Carbon Acid Polyol additivesVariety Flakes, 1 Graphene Glutaric Ethylene N/A micron thick, flakes, 5acid glycol 5-20 microns microns in in diameter diameter Weight 51.3 5.810.1 32.8 Percent, wt %

Printed film properties for change in concentration of carbon additivefrom 1.4 wt % to 5.8 wt % Sheet Resistance, Adhesion Range of Roughness,Ohm/sq/mil (0-5) μm 5.5 1 5-8

Change of acid from glutaric acid to malonic acid Ink Poly- Compo-carboxylic Other nent Nickel Carbon Acid Polyol additives VarietyFlakes, 1 Graphene Malonic Ethylene N/A micron thick, flakes, 5 acidglycol 5-20 microns microns in in diameter diameter Weight 57.2 1.2 8.233.4 Percent, wt %

Printed film properties for change of acid from glutaric acid to malonicacid Sheet Resistance, Adhesion Range of Roughness, Ohm/sq/mil (0-5) μm1.0 1 7-12

Change of alcohol from ethylene glycol to 1,3 propylene glycol Ink Poly-Compo- carboxylic Other nent Nickel Carbon Acid Polyol additives VarietyFlakes, 1 Graphene Glutaric 1,3 N/A micron thick, flakes, 5 acidpropylene 5-20 microns microns in glycol in diameter diameter Weight56.0 1.2 10.1 32.7 Percent, wt %

Printed film properties for change of alcohol from ethylene glycol to1,3 propylene glycol Sheet Resistance, Adhesion Range of Roughness,Ohm/sq/mil (0-5) μm 1.4 1 5-10

Addition of polyethylene glycol 600 as additive Ink Poly- Compo-carboxylic Other nent Nickel Carbon Acid Polyol additives VarietyFlakes, 1 Graphene Glutaric Ethylene Polyethylene micron thick, flakes,5 acid glycol glycol (600) 5-20 microns microns in as wetting indiameter diameter agent Weight 56.0 1.2 10.1 26.4 6.3 Percent, wt %

Printed film properties for addition of polyethylene glycol 600 asadditive Sheet Resistance, Adhesion Range of Roughness, Ohm/sq/mil (0-5)μm 600 1 5-10

Addition of N,N-Diethylhydroxlyamine as additive Ink PolycarboxylicComponent Nickel Carbon Acid Polyol Other additives Variety Flakes, 1Graphene Glutaric acid Ethylene N,N- micron flakes, 5 glycoldiethylhydroxylamine thick, 5-20 microns as antioxidant microns in indiameter diameter Weight 54.9 1.4 10.0 32.4 1.4 Percent, wt %

Printed film properties for addition of N,N-Diethylhydroxlyamine asadditive Sheet Resistance, Adhesion Range of Roughness, Ohm/sq/mil (0-5)μm 1.5 1 5-10

Adhesion performance, sheet resistance, printability performance, and/orother performance parameters for nickel films printed using nickel inkcompositions listed in the tables above can be measured by using one ormore measurement techniques described herein. For example, the adhesionfor listed compositions including nickel flakes and graphene flakes, asmeasured using the ISO test described above, was 1. Adhesion of thecompositions including filamentary nickel powder and graphite powderwere each 3. The resistance for some of the listed modified compositionswere comparable to the resistance of nickel film printed using thenickel ink composition of Table 1, but other printability parameters(e.g., thickness and smoothness) were not as desirable as that of thefilm printed using the composition listed in Table 1.

Example Variations in Ink Composition from the Example CompositionPresented in Table 1 and/or the Printing Parameters from the ExamplePrinting Parameters Presented in Table 2

Listed in the tables below are examples of nickel ink viscosity, nickelink compositions, and nickel ink printing parameters. The descriptionheading each table indicates the change made to the concentration of thepolyol component, as compared to the nickel ink composition of Table 1.Examples of measured sheet resistance (e.g., expressed in Ohm/sq/mil),adhesion, and range of roughness (e.g., expressed in μm) are alsoprovided in a corresponding nickel film properties table for each of thenickel films printed using the nickel ink compositions having the listedchange.

Change in viscosity by adding more ethylene glycol to the composition ofTable 1 Curing Curing Viscosity at Mesh Mesh temperature, time, 25° C.,cP type size ° C. min 6,000 Polyester 110 138 10 Ink componentPolycarboxylic Nickel Carbon Acid Polyol Variety Flakes, 1 micronGraphene Glutaric Ethylene thick, 5-20 flakes, 5 acid glycol microns inmicrons in diameter diameter Weight 54.2 1.1 9.9 34.8 Percent, wt %

Printed film properties for change in viscosity by adding more ethyleneglycol to the composition of Table 1 Sheet Resistance, Adhesion Range ofRoughness, Ohm/sq/mil (0-5) μm 1.0 1 7-12

Change in viscosity by adding less ethylene glycol to the composition ofTable 1 Curing Curing Viscosity at Mesh Mesh temperature, time, 25° C.,cP type size ° C. min 11,000 Polyester 110 138 10 Ink componentPolycarboxylic Nickel Carbon Acid Polyol Variety Flakes, 1 micronGraphene Glutaric Ethylene thick, 5-20 flakes, 5 acid glycol microns inmicrons in diameter diameter Weight 57.6 1.2 10.4 30.8 Percent, wt %

Printed film properties for change in viscosity adding by less ethyleneglycol to the composition of Table 1 Sheet Resistance, Adhesion Range ofRoughness, Ohm/sq/mil (0-5) μm 1.4 1 7-12

Listed in the tables below are examples of parameters of suitableprinting processes that can be used to print one or more nickel inkcompositions described herein. The description heading each tableprovides a printing parameter that is different from the printingprocess of Table 2. Examples of measured sheet resistance (e.g.,expressed in Ohm/sq/mil), adhesion, and range of roughness (e.g.,expressed in μm) are also provided in a corresponding nickel filmproperties table for each of the nickel films printed using the nickelink compositions having the listed change.

Change of substrate from Mylar to polyamide Curing Curing Viscosity atMesh Mesh temperature, time, 25° C., cP type size ° C. min 9,000Polyester 110 138 10

Printed film properties for change of substrate from Mylar to polyamideSheet Resistance, Adhesion Range of Roughness, Ohm/sq/mil (0-5) μm 0.8 15-7

Change of mesh type from polyester to a polyamide (e.g., nylon) CuringCuring Viscosity at Mesh Mesh temperature, time, 25° C., cP type size °C. min 9,000 Nylon 110 138 10

Printed film properties for change of mesh type from polyester to apolyamide (e.g., nylon) Sheet Resistance, Adhesion Range of Roughness,Ohm/sq/mil (0-5) μm 0.8 1 7-12

Change of mesh size from 110 to 135 Curing Curing Viscosity at Mesh Meshtemperature, time, 25° C., cP type size ° C. min Polyester 135 138 10

Printed film properties for change of mesh size from 110 to 135 SheetResistance, Adhesion Range of Roughness, Ohm/sq/mil (0-5) μm 0.8 1 7-12

Change of curing temperature from 138° C. to 143° C. Curing CuringViscosity at Mesh Mesh temperature, time, 25° C., cP type size ° C. minPolyester 110 143 10

Printed film properties for change of curing temperature from 138° C. to143° C. Sheet Resistance, Adhesion Range of Roughness, Ohm/sq/mil (0-5)μm 0.8 1 7-12

Change of curing time from 10 min to 5 min Curing Curing Viscosity atMesh Mesh temperature, time, 25° C., cP type size ° C. min Polyester 110138 5

Printed film properties for change of curing time from 10 min to 5 minSheet Resistance, Adhesion Range of Roughness, Ohm/sq/mil (0-5) μm 1.0 17-12Alternative Techniques

Ink Preparation Techniques

All kinds of mixing and dispersing techniques may be used, including,for example, mixing with a jar mill, mixing with a stir rod, mixing withmagnetic stirrer, mixing under heating, vortexing (e.g., using a Vortexmachine), shaking (using shakers), mixing by rotation, sonication,mortar and pestle, three-roll mill, combinations thereof, and the like.

Printing Techniques

“Printing” includes any and all printing processes, coating, rolling,spraying, layering, spin coating, lamination, and/or affixing processes,including, for example, screen printing, inkjet printing,electro-optical printing, electroink printing, photoresist and otherresist printing, thermal printing, laser jet printing, magneticprinting, pad printing, flexographic printing, hybrid offsetlithography, Gravure and other intaglio printing, die slot deposition,combinations thereof, and the like. Screen printing with different meshsizes and screen types are also possible.

Curing Conditions

A wide variety of temperature and curing time durations may be useddepending on solvents used. The temperature is generally from about 100°C. to about 200° C. Drying duration can vary from about 20 seconds toabout 1 hour.

The atmosphere can be ambient, inert, vacuum, combinations thereof, andthe like.

Alternative Components

Substrates

In some embodiments, substrates can be conductive and/or non-conductive.For example, a substrate can comprise graphite paper, graphene paper,polyester film (e.g., Mylar®), polyimide film, aluminum (Al) foil,copper (Cu) foil, stainless steel foil, carbon foam, polycarbonate film,paper, coated paper, plastic coated paper, fiber paper, cardboard,combinations thereof, and the like.

Nickel Powders

In some embodiments, the nickel comprises particles of any shape. Forexample, the nickel can comprise flakes, nano/microwires, spheres, arandom particles shape, combinations thereof, and the like. Nickelflakes may be available commercially (e.g., from Novamet SpecialtyProducts Corp., of Wyckoff, N.J.). Nickel particles may have a thicknessof less than about 5 microns. In some embodiments, nickel particles canhave a thickness of about 1 micron. Nickel particles may be of allprintable sizes (e.g., a length and/or a diameter from about 100nanometers (nm) to about 50 microns, from about 500 nanometers to about30 microns, from about 1 micron to about 20 microns, and from about 5microns to about 20 microns). An increased nickel particle dimension(e.g., a length and/or a diameter) may increase inter-flake contact,facilitating improved conductivity of the nickel film. In someembodiments, a nickel ink can include nickel particles having a sizewhich allows increased inter-particle contact for improved nickel inkconductivity. In some embodiments, nickel particles of a nickel ink canhave a size enabling increased inter-particle contact, whilefacilitating printing of the nickel ink and/or dispersion of the nickelflakes in the nickel ink.

Carbon Additive

In some embodiments, carbon particles can be of any shape. For example,carbon can comprise flakes, nano/microwires, spheres, a random particlesshape, combinations thereof, and the like. Carbon particles can be ofall printable sizes (e.g., a length and/or a diameter from about 100 nmto about 50 microns). For example, carbon particles may have a diameterof about 5 microns.

The carbon additive may be of any origin, including, for example,graphene, graphite, activated carbon, carbon nanotubes, carbonnanofibers, combinations thereof, and the like. In some embodiments,graphene flakes are commercially available (e.g., from XG Sciences,Inc., of Lansing, Mich.). In some embodiments, graphite is commerciallyavailable (e.g., from IMCAL Ltd., of Westlake, Ohio). Other carbonadditives may also be commercially available (e.g., carbon nanotubesfrom SouthWest Nanotechnologies Inc., of Norman, Okla., and carbonnanofibers from Pyrograf Products, Inc., of Cedarville, Ohio).

Components of the Polymer (Polyester)

Polymers or polyesters may be molten or dissolved polyesters (e.g.,polymers which contain the ester functional group in their main chain).A polyester may be made from a combination of acids and alcohols (e.g.,via polycondensation). Example acids can include: dicarboxylic acidssuch as propanedioic (malonic) acid, butanedioic (succinic) acid,pentanedioic (glutaric) acid, hexanedioic (adipic) acid, heptanedioic(pimelic) acid, octanedioic (suberic) acid, nonanedioic (azelaic) acid,decanedioic (sebacic) acid, undecanedioic acid, dodecanedioic acid,tridecanedioic (brassylic) acid, tetradecanedioic acid, pentadecanedioicacid, hexadecanedioic (thapsic) acid, octadecanedioic acid, maleic acid,fumaric acid, glutaconic acid, traumatic acid and/or muconic acid;tricarboxylic acids, such as citric acid, isocitric acid, aconitic acid,carballylic acid, trimesic acid, terephthalic acid; the like, andmixtures thereof.

Example alcohols can include: polyols (or liquid polyols), glycerols andglycols such as glycerin, diol, triol, tetraol, pentaol, ethyleneglycols, diethylene glycols, polyethylene glycols, propylene glycols,dipropylene glycols, glycol ethers, glycol ether acetates1,4-butanediol, 1,2-butanediol, 2,3-butanediol, 1,3-propanediol,1,4-butanediol, 1,5-pentanediol, 1,8-octanediol, 1,2-propanediol,1,3-butanediol, 1,2-pentanediol, etohexadiol, p-menthane-3,8-diol,2-methyl-2,4-pentanediol, combinations thereof, and the like.

A polyester may be made from hydroxicarboxilic acids (e.g., viapolycondensation): 4-hydroxybenzoic acid, glycolic acid, lactic acid,citric acid, mandelic acid, beta hydroxy acid, omega hydroxy acid,salicylic acid, 3-hydroxypropionic acid,6-hydroxynaphthalene-2-carboxylic acid, combinations thereof, and thelike.

Additives

Additives to inks can have several functions. For example, additives maybe a viscosity modifier, wetting agents, flow and leveling agents, andadhesion promoters, and/or corrosion inhibitors. In some embodiments,solvents can act as viscosity modifiers and wetting agents, flow andleveling agents, and adhesion promoters.

Example solvents include: water, alcohols such as methanol, ethanol,N-propanol (including 1-propanol, 2-propanol (isopropanol or IPA),1-methoxy-2-propanol), butanol (including 1-butanol, 2-butanol(isobutanol)), pentanol (including 1-pentanol, 2-pentanol, 3-pentanol),hexanol (including 1-hexanol, 2-hexanol, 3-hexanol), octanol, N-octanol(including 1-octanol, 2-octanol, 3-octanol), tetrahydrofurfuryl alcohol(THFA), cyclohexanol, cyclopentanol, terpineol; butyl lactone; etherssuch as methyl ethyl ether, diethyl ether, ethyl propyl ether, dibasicesters and polyethers; ketones, including diketones and cyclic ketones,such as cyclohexanone, cyclopentanone, cycloheptanone, cyclooctanone,acetone, benzophenone, acetylacetone, acetophenone, cyclopropanone,isophorone, methyl ethyl ketone; esters such ethyl acetate, dimethyladipate, proplyene glycol monomethyl ether acetate, dimethyl glutarate,dimethyl succinate, glycerin acetate, carboxylates; carbonates such aspropylene carbonate; glycol ethers, glycol ether acetates, tetramethylurea, n-methylpyrrolidone, acetonitrile, tetrahydrofuran (THF), dimethylformamide (DMF), N-methyl formamide (NMF), dimethyl sulfoxide (DMSO);thionyl chloride; sulfuryl chloride, 1,2-diaminoethane,propane-1,3-diamine, butane-1,4-diamine, (pentane-1,5-diamine,hexane-1,6-diamine, 1,2-diaminopropane, diphenylethylenediamine,diaminocyclohexane, o-xylylenediamine, o-phenylenediamine,m-phenylenediamine, hexane, decane, teradecane, styrene,1-vinyl-2-pyrolidone, toluene, pyridine, triethyl phosphate,combinations thereof, and the like.

In some embodiments, corrosion inhibitors can includeN,N-Diethylhydroxylamine, ascorbic acid, hydrazine, hexamine,phenylenediamine, benzotriazole, zinc dithiophosphate, tannic acid, zincphosphate, hexafluoroacetylacetone, combinations thereof, and the like.

In some embodiments, a nickel ink can include one or more otheradditives to facilitate a polymerization reaction (e.g., aco-polymerization reaction of an unsaturated polyester), such as benzoylperoxide, 2-butanol peroxide, 2,4-chlorobenzoyl peroxide, laurylperoxide, other peroxides, combinations thereof, and/or the like.

Example Embodiments

The following example embodiments identify some possible permutations ofcombinations of features disclosed herein, although other permutationsof combinations of features are also possible.

1. A conductive ink comprising:

-   -   a nickel component;    -   a polycarboxylic acid component; and    -   a polyol component, the polycarboxylic acid component and the        polyol component being reactable to form a polyester component.

2. The conductive ink of embodiment 1, further comprising an additivecomponent.

3. The conductive ink of embodiment 1 or 2, further comprising a carboncomponent.

4. The conductive ink of any one of embodiments 1 to 3, wherein thenickel component comprises at least one of nickel flakes, nickelnano/microwires, and nickel spheres.

5. The conductive ink of embodiment 4, wherein the nickel flakescomprise a thickness of less than about 5 microns.

6. The conductive ink of embodiment 4 or 5, wherein the nickel flakescomprise a diameter of about 500 nanometers to about 30 microns.

7. The conductive ink of any one of embodiments 1 to 6, wherein thenickel component comprises a filamentary nickel powder.

8. The conductive ink of embodiment 7, wherein the filamentary nickelpowder comprises a longest dimension in a range of about 2 microns toabout 10 microns.

9. The conductive ink of any one of embodiments 1 to 8, wherein thenickel component comprises at least one particle having a longestdimension in a range of about 100 nanometers to about 50 microns.

10. The conductive ink of any one of embodiments 1 to 8, wherein thenickel component comprises at least one particle having a longestdimension in a range of about 5 microns to about 20 microns.

11. The conductive ink of any one of embodiments 3 to 10, wherein thecarbon component comprises at least one of carbon flakes, carbonnano/microwires, and carbon spheres.

12. The conductive ink of any one of embodiments 3 to 11, wherein thecarbon component comprises at least one of graphene, graphite, activatedcarbon, carbon nanotubes, and carbon nanofibers.

13. The conductive ink of embodiment 12, wherein the graphene comprisesgraphene flakes.

14. The conductive ink of embodiment 13, wherein at least one of thegraphene flakes comprises a diameter of about 5 microns.

15. The conductive ink of embodiment 13 or 14, wherein at least one ofthe graphene flakes comprises a diameter of about 100 nanometers toabout 50 microns.

16. The conductive ink of any one of embodiments 12 to 15, wherein thegraphite comprises a graphite powder.

17. The conductive ink of any one of embodiments 1 to 16, wherein thepolycarboxylic acid component comprises a dicarboxylic acid.

18. The conductive ink of embodiment 17, wherein the dicarboxylic acidcomprises at least one of a propanedioic (malonic) acid, a butanedioic(succinic) acid, a pentanedioic (glutaric) acid, a hexanedioic (adipic)acid, a heptanedioic (pimelic) acid, a octanedioic (suberic) acid, anonanedioic (azelaic) acid, a decanedioic (sebacic) acid, anundecanedioic acid, a dodecanedioic acid, a tridecanedioic (brassylic)acid, a tetradecanedioic acid, a pentadecanedioic acid, ahexadecanedioic (thapsic) acid, an octadecanedioic acid, a maleic acid,a fumaric acid, a glutaconic acid, a traumatic acid and a muconic acid.

19. The conductive ink of any one of embodiments 1 to 18, wherein thepolycarboxylic acid component comprises a tricarboxylic acid.

20. The conductive ink of embodiment 19, wherein the tricarboxyliccomprises at least one of a citric acid, an isocitric acid, an aconiticacid, a carballylic acid, a trimesic acid, and a terephthalic acid.

21. The conductive ink of any one of embodiments 1 to 20, wherein thepolycarboxylic acid component comprises a hydroxicarboxilic acid.

22. The conductive ink of embodiment 21, wherein the hydroxicarboxilicacid comprises at least one of a 4-hydroxybenzoic acid, a glycolic acid,a lactic acid, citric acid, a mandelic acid, a beta hydroxy acid, anomega hydroxy acid, a salicylic acid, a 3-hydroxypropionic acid, and a6-hydroxynaphthalene-2-carboxylic acid.

23. The conductive ink of embodiment 22, wherein the polyol componentcomprises at least one of a glycerol and a glycol.

24. The conductive ink of embodiment 22 or 23, wherein the polyolcomponent comprises at least one of a glycerin, a diol, a triol, atetraol, a pentaol, an ethylene glycol, a diethylene glycol, apolyethylene glycol, a propylene glycol, a dipropylene glycol, a glycolether, a glycol ether acetates 1,4-butanediol, a 1,2-butanediol, a2,3-butanediol, a 1,3-propanediol, a 1,4-butanediol, a 1,5-pentanediol,a 1,8-octanediol, a 1,2-propanediol, a 1,3-butanediol, a1,2-pentanediol, an etohexadiol, a p-menthane-3,8-diol, and a2-methyl-2,4-pentanediol.

25. The conductive ink of any one of embodiments 2 to 24, wherein theadditive component comprises at least one of a viscosity modifier, awetting agent, a flow and leveling agent, an adhesion promoter, and acorrosion inhibitor.

26. The conductive ink of embodiment 25, wherein the wetting agentcomprises a polyethylene glycol.

27. The conductive ink of embodiment 25 or 26, wherein the corrosioninhibitor comprises at least one of an N,N-diethylhydroxylamine, anascorbic acid, a hydrazine, a hexamine, a phenylenediamine, abenzotriazole, a zinc dithiophosphate, a tannic acid, a zinc phosphate,and a hexafluoroacetylacetone.

28. The conductive ink of any one of embodiments 2 to 27, wherein theadditive component comprises a solvent.

29. The conductive ink of embodiment 28, wherein the solvent comprisesat least one of a viscosity modifier, a wetting agent, a flow andleveling agent, and an adhesion promoter.

30. The conductive ink of embodiment 28 or 29, wherein the solventcomprises at least one of an alcohol and water.

31. The conductive ink of embodiment 30, wherein the alcohol comprisesat least one of a methanol, an ethanol, a N-propanol, a butanol,pentanol, hexanol, an octanol, an N-octanol, a tetrahydrofurfurylalcohol (THFA), a cyclohexanol, a cyclopentanol, and a terpineol.

32. The conductive ink of embodiment 31, wherein the N-propanolcomprises at least one of a 1-propanol, a 2-propanol, and a1-methoxy-2-propanol.

33. The conductive ink of embodiment 31, wherein the butanol comprisesat least one of a 1-butanol and a 2-butanol.

34. The conductive ink of embodiment 31, wherein the pentanol comprisesat least one of a 1-pentanol, a 2-pentanol, and a 3-pentanol.

35. The conductive ink of embodiment 31, wherein the hexanol comprisesat least one of a 1-hexanol, a 2-hexanol, and a 3-hexanol.

36. The conductive ink of embodiment 31, wherein the N-octanol comprisesat least one of a 1-octanol, a 2-octanol, and a 3-octanol.

37. The conductive ink of any one of embodiments 2 to 36, wherein theadditive component comprises a butyl lactone.

38. The conductive ink of any one of embodiments 2 to 37, wherein theadditive component comprises an ether.

39. The conductive ink of embodiment 38, wherein the ether comprises atleast one of a methyl ethyl ether, a diethyl ether, an ethyl propylether, and a polyether.

40. The conductive ink of any one of embodiments 2 to 39, wherein theadditive component comprises a ketone.

41. The conductive ink of embodiment 40, wherein the ketone comprises atleast one of an acetone and a methyl ethyl ketone.

42. The conductive ink of embodiment 40 or 41, wherein the ketonecomprises at least one of a diketone and a cyclic ketone.

43. The conductive ink of embodiment 42, wherein the cyclic ketonecomprises at least one of a cyclohexanone, a cyclopentanone, acycloheptanone, a cyclooctanone, a benzophenone, an acetylacetone, anacetophenone, a cyclopropanone, and an isophorone.

44. The conductive ink of any one of embodiments 2 to 43, wherein theadditive component comprises an ester.

45. The conductive ink of embodiment 44, wherein the ester comprises atleast one of a dibasic ester, an ethyl acetate, a dimethyl adipate, aproplyene glycol monomethyl ether acetate, a dimethyl glutarate, adimethyl succinate, a glycerin acetate, and a carboxylate.

46. The conductive ink of any one of embodiments 2 to 45, wherein theadditive component comprises a carbonate.

47. The conductive ink of embodiment 46, wherein the carbonate comprisesa propylene carbonate.

48. The conductive ink of any one of embodiments 2 to 47, wherein theadditive component comprises at least one of a glycol ether, a glycolether acetate, a tetramethyl urea, an n-methylpyrrolidone, anacetonitrile, a tetrahydrofuran (THF), a dimethyl formamide (DMF), anN-methyl formamide (NMF), a dimethyl sulfoxide (DMSO), a thionylchloride, a sulfuryl chloride, a 1,2-diaminoethane, apropane-1,3-diamine, a butane-1,4-diamine, a pentane-1,5-diamine, ahexane-1,6-diamine, a 1,2-diaminopropane, a diphenylethylenediamine, adiaminocyclohexane, an o-xylylenediamine, an o-phenylenediamine, anm-phenylenediamine, a hexane, a decane, a teradecane, a styrene, a1-vinyl-2-pyrolidone, a toluene, a pyridine, and a triethyl phosphate.

49. The conductive ink of any one of embodiments 1 to 48, wherein theconductive ink has a viscosity at about 25° C. in a range from about5,000 centipoise to about 11,000 centipoise.

50. The conductive ink of any one of embodiments 1 to 49, wherein thenickel component is in a range from about 50 wt % to about 60 wt %.

51. The conductive ink of any one of embodiments 1 to 49, wherein thenickel component is in a range from about 35 wt % to about 65 wt %.

52. The conductive ink of any one of embodiments 3 to 51, wherein thecarbon component is in a range from about 0.5 wt % to about 2.5 wt %.

53. The conductive ink of any one of embodiments 3 to 51, wherein thecarbon component is less than about 10 wt %.

54. The conductive ink of any of embodiments 1 to 53, wherein thepolycarboxylic acid component is in a range from about 5 wt % to about15 wt %.

55. The conductive ink of any of embodiments 1 to 54, wherein the polyolcomponent is in a range from about 25 wt % to about 40 wt %.

56. The conductive ink of any of embodiments 1 to 54, wherein the polyolcomponent is in a range from about 15 wt % to about 60 wt %.

57. The conductive ink of any of embodiments 2 to 56, wherein theadditive component is less than about 10%.

58. A conductive film comprising:

-   -   a nickel component; and    -   a polyester component.

59. The conductive film of embodiment 58, further comprising an additivecomponent.

60. The conductive film of embodiment 58 or 59, further comprising acarbon component.

61. The conductive film of any one of embodiments 58 to 60, wherein thenickel component comprises at least one of nickel flakes, nickelnano/microwires, and nickel spheres.

62. The conductive film of embodiment 61, wherein the nickel flakescomprise a thickness of less than about 5 microns.

63. The conductive film of embodiment 61 or 62, wherein the nickelflakes comprise a diameter of about 500 nanometers to about 30 microns.

64. The conductive film of any one of embodiments 58 to 63, wherein thenickel component comprises a filamentary nickel powder.

65. The conductive film of embodiment 64, wherein the filamentary nickelpowder comprises a longest dimension in a range of about 2 microns toabout 10 microns.

66. The conductive film of any one of embodiments 58 to 65, wherein thenickel component comprises at least one particle having a longestdimension in a range of about 100 nanometers to about 50 microns.

67. The conductive film of any one of embodiments 58 to 65, wherein thenickel component comprises at least one particle having a longestdimension in a range of about 5 microns to about 20 microns.

68. The conductive film of any one of embodiments 60 to 67, wherein thecarbon component comprises at least one of carbon flakes, carbonnano/microwires, and carbon spheres.

69. The conductive film of any one of embodiments 60 to 68, wherein thecarbon component comprises at least one of graphene, graphite, activatedcarbon, carbon nanotubes, and carbon nanofibers.

70. The conductive film of embodiment 69, wherein the graphene comprisesgraphene flakes.

71. The conductive film of embodiment 70, wherein at least one of thegraphene flakes comprises a diameter of about 5 microns.

72. The conductive film of any one of embodiments 70 or 71, wherein atleast one of the graphene flakes comprises a diameter of about 100nanometers to about 50 microns.

73. The conductive film of any one of embodiments 69 to 72, wherein thegraphite comprises a graphite powder.

74. The conductive film of any one of embodiments 58 to 73, wherein thepolyester component is formed in situ from a polycarboxylic acidcomponent and a polyol component.

75. The conductive film of any one of embodiments 58 to 74, wherein theconductive film has a sheet resistance in a range from about 0.5ohm/sq/mil to about 1.5 ohm/sq/mil.

76. The conductive film of any one of embodiments 58 to 75, wherein theconductive film has a thickness in a range from about 4 microns to about40 microns.

77. The conductive film of any one of embodiments 58 to 76, wherein theconductive film can be printed onto a substrate.

78. The conductive film of embodiment 77, wherein the substratecomprises a conductive substrate or a non-conductive substrate.

79. The conductive film of embodiment 77 or 78, wherein the substratecomprises at least one of a graphite paper, a graphene paper, apolyester film, a polyimide film, an aluminum foil, a copper foil, astainless steel foil, a carbon foam, a polycarbonate film, a paper, acoated paper, a plastic coated paper, a fiber paper, and a cardboard.

80. A method of fabricating a conductive ink, the method comprising:

-   -   dispersing a nickel component in a solvent component; and    -   dispersing a polyester component in the solvent component.

81. The method of embodiment 80, further comprising dispersing a carboncomponent in the solvent component.

82. The method of embodiment 80 or 81, wherein dispersing the nickelcomponent in the solvent component is before dispersing the polyestercomponent in the solvent component.

83. The method of any one of embodiments 80 to 82, wherein dispersingthe nickel component in the solvent component is after dispersing thepolyester component in the solvent component.

84. The method of any one of embodiments 80 to 83, wherein dispersingthe nickel component in the solvent component is before dispersing thecarbon component in the solvent component.

85. The method of any one of embodiments 80 to 83, wherein dispersingthe nickel component in the solvent component is after dispersing thecarbon component in the solvent component.

86. The method of any one of embodiments 80 to 85, wherein dispersingthe carbon component in the solvent component is before dispersing thepolyester component in the solvent component.

87. The method of any one of embodiments 80 to 85, wherein dispersingthe carbon component in the solvent component is after dispersing thepolyester component in the solvent component.

88. The method of any one of embodiments 80 to 87, further comprisingadding an additive component to the solvent component.

89. The method of embodiment 88, wherein adding the additive componentto the solvent component is before dispersing the nickel component inthe solvent.

90. The method of embodiment 88, wherein adding the additive componentto the solvent component is after dispersing the nickel component in thesolvent.

91. The method of any one of embodiments 88 to 90, wherein adding theadditive component to the solvent component is before dispersing thepolyester component in the solvent.

92. The method of any one of embodiments 88 to 90, wherein adding theadditive component to the solvent component is after dispersing thepolyester component in the solvent.

93. The method of any one of embodiments 88 to 92, wherein adding theadditive component to the solvent component is before dispersing thecarbon component in the solvent.

94. The method of any one of embodiments 88 to 92, wherein adding theadditive component to the solvent component is after dispersing thecarbon component in the solvent.

95. The method of any one of embodiments 80 to 94, wherein theconductive ink is printable onto a substrate.

96. The method of embodiment 95, wherein the substrate comprises aconductive substrate or a non-conductive substrate.

97. The method of embodiment 95 or 96, wherein the substrate comprisesat least one of a graphite paper, a graphene paper, a polyester film, apolyimide film, an aluminum foil, a copper foil, a stainless steel foil,a carbon foam, a polycarbonate film, a paper, a coated paper, a plasticcoated paper, a fiber paper, and a cardboard.

98. The method of any one of embodiments 80 to 97, wherein the nickelcomponent comprises at least one of nickel flakes, nickelnano/microwires, and nickel spheres.

99. The method of embodiment 98, wherein the nickel flakes comprise athickness of less than about 5 microns.

100. The method of embodiment 98 or 99, wherein the nickel flakescomprise a diameter of about 500 nanometers to about 30 microns.

101. The method of any one of embodiments 80 to 100, wherein the nickelcomponent comprises a filamentary nickel powder.

102. The method of embodiment 101, wherein the filamentary nickel powdercomprises a longest dimension in a range of about 2 microns to about 10microns.

103. The method of any one of embodiments 80 to 102, wherein the nickelcomponent comprises at least one particle having a longest dimension ina range of about 100 nanometers to about 50 microns.

104. The method of any one of embodiments 81 to 103, wherein the carboncomponent comprises at least one of carbon flakes, carbonnano/microwires, and carbon spheres.

105. The method of any one of embodiments 81 to 104, wherein the carboncomponent comprises at least one of graphene, graphite, activatedcarbon, carbon nanotubes, and carbon nanofibers.

106. The method of embodiment 105, wherein the graphene comprisesgraphene flakes.

107. The method of embodiment 106, wherein at least one of the grapheneflakes comprises a diameter of about 5 microns.

108. The method of embodiment 105 or 106, wherein at least one of thegraphene flakes comprises a diameter of about 100 nanometers to about 50microns.

109. The method of any one of embodiments 105 to 108, wherein thegraphite comprises a graphite powder.

110. The method of any one of embodiments 80 to 109, wherein thepolyester component is formed from a polycarboxylic acid component and apolyol component.

111. The method of embodiment 110, wherein the polycarboxylic acidcomponent comprises a dicarboxylic acid.

112. The method of embodiment 111, wherein the dicarboxylic acidcomprises at least one of a propanedioic (malonic) acid, a butanedioic(succinic) acid, a pentanedioic (glutaric) acid, a hexanedioic (adipic)acid, a heptanedioic (pimelic) acid, a octanedioic (suberic) acid, anonanedioic (azelaic) acid, a decanedioic (sebacic) acid, anundecanedioic acid, a dodecanedioic acid, a tridecanedioic (brassylic)acid, a tetradecanedioic acid, a pentadecanedioic acid, ahexadecanedioic (thapsic) acid, an octadecanedioic acid, a maleic acid,a fumaric acid, a glutaconic acid, a traumatic acid and a muconic acid.

113. The method of any one of embodiments 110 to 112, wherein thepolycarboxylic acid component comprises a tricarboxylic acid.

114. The method of embodiment 113, wherein the tricarboxylic comprisesat least one of a citric acid, an isocitric acid, an aconitic acid, acarballylic acid, a trimesic acid, and a terephthalic acid.

115. The method of any one of embodiments 110 to 114, wherein thepolycarboxylic acid component comprises a hydroxicarboxilic acid.

116. The method of embodiment 115, wherein the hydroxicarboxilic acidcomprises at least one of a 4-hydroxybenzoic acid, a glycolic acid, alactic acid, citric acid, a mandelic acid, a beta hydroxy acid, an omegahydroxy acid, a salicylic acid, a 3-hydroxypropionic acid, and a6-hydroxynaphthalene-2-carboxylic acid.

117. The method of any one of embodiments 110 to 116, wherein the polyolcomponent comprises at least one of a glycerol and a glycol.

118. The method of embodiment 110 to 117, wherein the polyol componentcomprises at least one of a glycerin, a diol, a triol, a tetraol, apentaol, an ethylene glycol, a diethylene glycol, a polyethylene glycol,a propylene glycol, a dipropylene glycol, a glycol ether, a glycol etheracetates 1,4-butanediol, a 1,2-butanediol, a 2,3-butanediol, a1,3-propanediol, a 1,4-butanediol, a 1,5-pentanediol, a 1,8-octanediol,a 1,2-propanediol, a 1,3-butanediol, a 1,2-pentanediol, an etohexadiol,a p-menthane-3,8-diol, and a 2-methyl-2,4-pentanediol.

119. The method of any one of embodiments 88 to 118, wherein theadditive component comprises at least one of a viscosity modifier, awetting agent, a flow and leveling agent, an adhesion promoter, and acorrosion inhibitor.

120. The method of embodiment 119, wherein the wetting agent comprises apolyethylene glycol.

121. The method of embodiment 119 or 120, wherein the corrosioninhibitor comprises at least one of an N,N-diethylhydroxylamine, anascorbic acid, a hydrazine, a hexamine, a phenylenediamine, abenzotriazole, a zinc dithiophosphate, a tannic acid, a zinc phosphate,and a hexafluoroacetylacetone.

122. The method of any one of embodiments 88 to 121, wherein theadditive component comprises a solvent.

123. The method of embodiment 122, wherein the solvent comprises atleast one of a viscosity modifier, a wetting agent, a flow and levelingagent and an adhesion promoter.

124. The method of any one of embodiment 122 or 123, wherein the solventcomprises at least one of an alcohol and water.

125. The method of embodiment 124, wherein the alcohol comprises atleast one of a methanol, an ethanol, a N-propanol, a butanol, pentanol,hexanol, an octanol, an N-octanol, a tetrahydrofurfuryl alcohol (THFA),a cyclohexanol, a cyclopentanol, and a terpineol.

126. The method of embodiment 125, wherein the N-propanol comprises atleast one of a 1-propanol, a 2-propanol, and a 1-methoxy-2-propanol.

127. The method of embodiment 125, wherein the butanol comprises atleast one of a 1-butanol and a 2-butanol.

128. The method of embodiment 125, wherein the pentanol comprises atleast one of a 1-pentanol, a 2-pentanol, and a 3-pentanol.

129. The method of embodiment 125, wherein the hexanol comprises atleast one of a 1-hexanol, a 2-hexanol, and a 3-hexanol.

130. The method of embodiment 125, wherein the N-octanol comprises atleast one of a 1-octanol, a 2-octanol, and a 3-octanol.

131. The method of any one of embodiments 88 to 130, wherein theadditive component comprises a butyl lactone.

132. The method of any one of embodiments 88 to 131, wherein theadditive component comprises an ether.

133. The method of embodiment 132, wherein the ether comprises at leastone of a methyl ethyl ether, a diethyl ether, an ethyl propyl ether, anda polyether.

134. The method of any one of embodiments 88 to 133, wherein theadditive component comprises a ketone.

135. The method of embodiment 134, wherein the ketone comprises at leastone of an acetone and a methyl ethyl ketone.

136. The method of embodiments 134 or 135, wherein the ketone comprisesat least one of a diketone and a cyclic ketone.

137. The method of embodiment 136, wherein the cyclic ketone comprisesat least one of a cyclohexanone, a cyclopentanone, a cycloheptanone, acyclooctanone, a benzophenone, an acetylacetone, an acetophenone, acyclopropanone, and an isophorone.

138. The method of any one of embodiments 88 to 137, wherein theadditive component comprises an ester.

139. The method of embodiment 138, wherein the ester comprises at leastone of a dibasic ester, an ethyl acetate, a dimethyl adipate, aproplyene glycol monomethyl ether acetate, a dimethyl glutarate, adimethyl succinate, a glycerin acetate, and a carboxylate.

140. The method of any one of embodiments 88 to 139, wherein theadditive component comprises a carbonate.

141. The method of embodiment 140, wherein the carbonate comprises apropylene carbonate.

142. The method of any one of embodiments 88 to 141, wherein theadditive component comprises at least one of a glycol ether, a glycolether acetate, a tetramethyl urea, an n-methylpyrrolidone, anacetonitrile, a tetrahydrofuran (THF), a dimethyl formamide (DMF), anN-methyl formamide (NMF), a dimethyl sulfoxide (DMSO), a thionylchloride, a sulfuryl chloride, a 1,2-diaminoethane, apropane-1,3-diamine, a butane-1,4-diamine, a pentane-1,5-diamine, ahexane-1,6-diamine, a 1,2-diaminopropane, a diphenylethylenediamine, adiaminocyclohexane, an o-xylylenediamine, an o-phenylenediamine, anm-phenylenediamine, a hexane, a decane, a teradecane, a styrene, a1-vinyl-2-pyrolidone, a toluene, a pyridine, and a triethyl phosphate.

143. The method of any one of embodiments 80 to 142, wherein theconductive ink has a viscosity at about 25° C. in a range from about5,000 centipoise to about 11,000 centipoise.

144. The method of any one of embodiments 80 to 143, wherein the nickelcomponent is in a range from about 50 wt % to about 60 wt %.

145. The method of any one of embodiments 80 to 143, wherein the nickelcomponent is in a range from about 35 wt % to about 65 wt %.

146. The method of any one of embodiments 81 to 145, wherein the carboncomponent is in a range from about 0.5 wt % to about 2.5 wt %.

147. The method of any one of embodiments 81 to 145, wherein the carboncomponent is less than about 10 wt %.

148. The method of any of embodiments 88 to 147, wherein the additivecomponent is less than about 10 wt %.

149. A method of fabricating a conductive film, the method comprising:

-   -   printing a conductive ink on a substrate, the conductive ink        comprising:        -   a nickel component, and        -   a polyester component; and    -   curing the printed conductive ink.

150. The method of embodiment 149, wherein printing comprises at leastone of a screen printing process, a coating process, a rolling process,a spraying process, a layering process, a spin coating process, alamination process, an affixing process, an inkjet printing process, anelectro-optical printing process, an electroink printing process, aresist printing process, a thermal printing process, a laser jetprinting process, a magnetic printing process, a pad printing process, aflexographic printing process, a hybrid offset lithography process, aintaglio printing process, and a die slot deposition process.

151. The method of embodiment 150, wherein the screen printing processcomprises using a polyester screen.

152. The method of embodiment 150 or 151, wherein the screen printingprocess comprises using a polyamide screen.

153. The method of any one of embodiments 150 to 152, wherein the screenprinting process comprises using a screen having a mesh size of about110.

154. The method of any one of embodiments 150 to 153, wherein the screenprinting process comprises using a screen having a mesh size of about135.

155. The method of any one of embodiments 149 to 154, wherein thesubstrate comprises a conductive substrate or a non-conductivesubstrate.

156. The method of any one of embodiments 149 to 155, wherein thesubstrate comprises at least one of a graphite paper, a graphene paper,a polyester film, a polyimide film, an aluminum foil, a copper foil, astainless steel foil, a carbon foam, a polycarbonate film, a paper, acoated paper, a plastic coated paper, a fiber paper, and a cardboard.

157. The method of any one of embodiments 149 to 156, wherein curing theprinted conductive ink comprises heating the printed conductive ink andthe substrate to a temperature in a range from about 100° C. to about200° C.

158. The method of any one of embodiments 149 to 156, wherein curing theprinted conductive ink comprises heating the printed conductive ink andthe substrate to a temperature in a range from about 130° C. to about140° C.

159. The method of any one of embodiments 149 to 158, wherein curing theprinted conductive ink comprises heating the printed conductive ink andthe substrate for a duration from about 20 seconds to about 1 hour.

160. The method of any one of embodiments 149 to 158, wherein curing theprinted conductive ink comprises heating the printed conductive ink andthe substrate for a duration from about 3 minutes to about 10 minutes.

161. The method of any one of embodiments 149 to 160, wherein the nickelcomponent comprises at least one of nickel flakes, nickelnano/microwires, and nickel spheres.

162. The method of embodiment 161, wherein the nickel flakes comprise athickness of less than about 5 microns.

163. The method of embodiment 161 or 162, wherein the nickel flakescomprise a diameter of about 500 nanometers to about 30 microns.

164. The method of any one of embodiments 149 to 163, wherein the nickelcomponent comprises a filamentary nickel powder.

165. The method of embodiment 164, wherein the filamentary nickel powdercomprises a longest dimension in a range of about 2 microns to about 10microns.

166. The method of any one of embodiments 149 to 165, wherein the nickelcomponent comprises at least one particle having a longest dimension ina range of about 100 nanometers to about 50 microns.

167. The method of any one of embodiments 149 to 166, wherein theconductive ink comprises a carbon component.

168. The method of embodiment 167, wherein the carbon componentcomprises at least one of carbon flakes, carbon nano/microwires, andcarbon spheres.

169. The method of embodiment 167 or 168, wherein the carbon componentcomprises at least one of graphene, graphite, activated carbon, carbonnanotubes, and carbon nanofibers.

170. The method of embodiment 169, wherein the graphene comprisesgraphene flakes.

171. The method of embodiment 170, wherein at least one of the grapheneflakes comprises a diameter of about 5 microns.

172. The method of embodiment 170 or 171, wherein at least one of thegraphene flakes comprises a diameter of about 100 nanometers to about 50microns.

173. The method of any one of embodiments 169 to 172, wherein thegraphite comprises a graphite powder.

174. The method of any one of embodiments 149 to 173, wherein thepolyester component is formed from a polycarboxylic acid component and apolyol component.

175. The method of embodiment 174, wherein the polycarboxylic acidcomponent comprises a dicarboxylic acid.

176. The method of embodiment 175 wherein the dicarboxylic acid at leastone of a propanedioic (malonic) acid, a butanedioic (succinic) acid, apentanedioic (glutaric) acid, a hexanedioic (adipic) acid, aheptanedioic (pimelic) acid, a octanedioic (suberic) acid, a nonanedioic(azelaic) acid, a decanedioic (sebacic) acid, an undecanedioic acid, adodecanedioic acid, a tridecanedioic (brassylic) acid, atetradecanedioic acid, a pentadecanedioic acid, a hexadecanedioic(thapsic) acid, an octadecanedioic acid, a maleic acid, a fumaric acid,a glutaconic acid, a traumatic acid and a muconic acid.

177. The method of any one of embodiments 174 to 176, wherein thepolycarboxylic acid component comprises a tricarboxylic acid.

178. The method of embodiment 177, wherein the tricarboxylic comprisesat least one of a citric acid, an isocitric acid, an aconitic acid, acarballylic acid, a trimesic acid, and a terephthalic acid.

179. The method of any one of embodiments 174 to 178, wherein thepolycarboxylic acid component comprises a hydroxicarboxilic acid.

180. The method of embodiment 179, wherein the hydroxicarboxilic acidcomprises at least one of a 4-hydroxybenzoic acid, a glycolic acid, alactic acid, citric acid, a mandelic acid, a beta hydroxy acid, an omegahydroxy acid, a salicylic acid, a 3-hydroxypropionic acid, and a6-hydroxynaphthalene-2-carboxylic acid.

181. The method of any one of embodiments 174 to 180, wherein the polyolcomponent comprises at least one of a glycerol and a glycol.

182. The method of any one of embodiments 174 to 181, wherein the polyolcomponent comprises at least one of a glycerin, a diol, a triol, atetraol, a pentaol, an ethylene glycol, a diethylene glycol, apolyethylene glycol, a propylene glycol, a dipropylene glycol, a glycolether, a glycol ether acetates 1,4-butanediol, a 1,2-butanediol, a2,3-butanediol, a 1,3-propanediol, a 1,4-butanediol, a 1,5-pentanediol,a 1,8-octanediol, a 1,2-propanediol, a 1,3-butanediol, a1,2-pentanediol, an etohexadiol, a p-menthane-3,8-diol, and a2-methyl-2,4-pentanediol.

183. The method of any one of embodiments 149 to 182, wherein theconductive ink comprises an additive component.

184. The method of embodiment 183, wherein the additive componentcomprises at least one of a viscosity modifier, a wetting agent, a flowand leveling agent, an adhesion promoter, and a corrosion inhibitor.

185. The method of embodiment 184, wherein the wetting agent comprises apolyethylene glycol.

186. The method of embodiment 184 or 185, wherein the corrosioninhibitor comprises at least one of an N,N-diethylhydroxylamine, anascorbic acid, a hydrazine, a hexamine, a phenylenediamine, abenzotriazole, a zinc dithiophosphate, a tannic acid, a zinc phosphate,and a hexafluoroacetylacetone.

187. The method of any one of embodiments 183 to 186, wherein theadditive component comprises a solvent.

188. The method of embodiment 187, wherein the solvent comprises atleast one of a viscosity modifier, a wetting agent, a flow and levelingagent and an adhesion promoter.

189. The method of embodiment 187 or 188, wherein the solvent comprisesat least one of an alcohol and water.

190. The method of embodiment 189, wherein the alcohol comprises atleast one of a methanol, an ethanol, a N-propanol, a butanol, pentanol,hexanol, an octanol, an N-octanol, a tetrahydrofurfuryl alcohol (THFA),a cyclohexanol, a cyclopentanol, and a terpineol.

191. The method of embodiment 190, wherein the N-propanol comprises atleast one of a 1-propanol, a 2-propanol, and a 1-methoxy-2-propanol.

192. The method of embodiment 190, wherein the butanol comprises atleast one of a 1-butanol and a 2-butanol.

193. The method of embodiment 190, wherein the pentanol comprises atleast one of a 1-pentanol, a 2-pentanol, and a 3-pentanol.

194. The method of embodiment 190, wherein the hexanol comprises atleast one of a 1-hexanol, a 2-hexanol, and a 3-hexanol.

195. The method of embodiment 190, wherein the N-octanol comprises atleast one of a 1-octanol, a 2-octanol, and a 3-octanol.

196. The method of any one of embodiments 183 to 195, wherein theadditive component comprises a butyl lactone.

197. The method of any one of embodiments 183 to 196, wherein theadditive component comprises an ether.

198. The method of embodiment 197, wherein the ether comprises at leastone of a methyl ethyl ether, a diethyl ether, an ethyl propyl ether, anda polyether.

199. The method of any one of embodiments 183 to 198, wherein theadditive component comprises a ketone.

200. The method of embodiment 199, wherein the ketone comprises at leastone of an acetone and a methyl ethyl ketone.

201. The method of embodiment 199 or 200, wherein the ketone comprisesat least one of a diketone and a cyclic ketone.

202. The method of embodiment 201, wherein the cyclic ketone comprisesat least one of a cyclohexanone, a cyclopentanone, a cycloheptanone, acyclooctanone, a benzophenone, an acetylacetone, an acetophenone, acyclopropanone, and an isophorone.

203. The method of any one of embodiments 183 to 202, wherein theadditive component comprises an ester.

204. The method of embodiment 203, wherein the ester comprises at leastone of a dibasic ester, an ethyl acetate, a dimethyl adipate, aproplyene glycol monomethyl ether acetate, a dimethyl glutarate, adimethyl succinate, a glycerin acetate, and a carboxylate.

205. The method of any one of embodiments 183 to 204, wherein theadditive component comprises a carbonate.

206. The method of embodiment 205 wherein the carbonate comprises apropylene carbonate.

207. The method of any one of embodiments 183 to 206, wherein theadditive component comprises at least one of a glycol ether, a glycolether acetate, a tetramethyl urea, an n-methylpyrrolidone, anacetonitrile, a tetrahydrofuran (THF), a dimethyl formamide (DMF), anN-methyl formamide (NMF), a dimethyl sulfoxide (DMSO), a thionylchloride, a sulfuryl chloride, a 1,2-diaminoethane, apropane-1,3-diamine, a butane-1,4-diamine, a pentane-1,5-diamine, ahexane-1,6-diamine, a 1,2-diaminopropane, a diphenylethylenediamine, adiaminocyclohexane, an o-xylylenediamine, an o-phenylenediamine, anm-phenylenediamine, a hexane, a decane, a teradecane, a styrene, a1-vinyl-2-pyrolidone, a toluene, a pyridine, and a triethyl phosphate.

208. The method of any one of embodiments 149 to 207, wherein theconductive ink comprises a viscosity at 25° C. in a range from about5,000 centipoise to about 11,000 centipoise.

209. The method of any one of embodiments 189 to 251, wherein the nickelcomponent is in a range from about 50 wt % to about 60 wt %.

210. The method of any one of embodiments 189 to 251, wherein the nickelcomponent is in a range from about 35 wt % to about 65 wt %.

211. The method of any one of embodiments 207 to 253, wherein the carboncomponent is in a range from about 0.5 wt % to about 2.5 wt %.

212. The method of any one of embodiments 207 to 253, wherein the carboncomponent is less than about 10 wt %.

213. The method of any of embodiments 226 to 258, wherein the additivecomponent is less than about 10 wt %.

214. A method of fabricating a conductive ink, the method comprising:

-   -   dispersing a nickel component in a polyol component;    -   dispersing a polycarboxylic acid component in the polyol        component, the polycarboxylic acid component and the polyol        component being reactable to form a polyester component.

215. The method of embodiment 214, wherein dispersing the polycarboxylicacid component in the polyol component forms the polyester component insitu.

216. The method of embodiment 214 or 215, further comprising dispersinga carbon component in the polyol component.

217. The method of any one of embodiments 214 to 216, wherein dispersingthe nickel component in the polyol component is before dispersing thepolycarboxylic acid component in the polyol component.

218. The method of any one of embodiments 214 to 216, wherein dispersingthe nickel component in the polyol component is after dispersing thepolycarboxylic acid component in the polyol component.

219. The method of any one of embodiments 216 to 218, wherein dispersingthe nickel component in the polyol component is before dispersing thecarbon component in the polyol component.

220. The method of any one of embodiments 216 to 218, wherein dispersingthe nickel component in the polyol component is after dispersing thecarbon component in the polyol component.

221. The method of any one of embodiments 216 to 220, wherein dispersingthe carbon component in the polyol component is before dispersing thepolycarboxylic acid component in the polyol component.

222. The method of any one of embodiments 216 to 220, wherein dispersingthe carbon component in the polyol component is after dispersing thepolycarboxylic acid component in the polyol component.

223. The method of any one of embodiments 214 to 222, further comprisingadding an additive component.

224. The method of embodiment 223, wherein adding the additive componentis before dispersing the nickel component in the polyol component.

225. The method of embodiment 223, wherein adding the additive componentis after dispersing the nickel component in the polyol component.

226. The method of any one of embodiments 223 to 225, wherein adding theadditive component is before dispersing the polycarboxylic acidcomponent in the polyol component.

227. The method of any one of embodiments 223 to 225, wherein adding theadditive component is after dispersing the polycarboxylic acid componentin the polyol component.

228. The method of any one of embodiments 223 to 227, wherein adding theadditive component is before dispersing the carbon component in thepolyol component.

229. The method of any one of embodiments 223 to 227, wherein adding theadditive component is after dispersing the carbon component in thepolyol component.

230. The method of any one of embodiments 214 to 229, wherein theconductive ink is printable onto a substrate.

231. The method of embodiment 230, wherein the substrate comprises aconductive substrate or a non-conductive substrate.

232. The method of embodiment 230 or 231, wherein the substratecomprises at least one of a graphite paper, a graphene paper, apolyester film, a polyimide film, an aluminum foil, a copper foil, astainless steel foil, a carbon foam, a polycarbonate film, a paper, acoated paper, a plastic coated paper, a fiber paper, and a cardboard.

233. The method of any one of embodiments 214 to 232, wherein the nickelcomponent comprises at least one of nickel flakes, nickelnano/microwires, and nickel spheres.

234. The method of embodiment 233, wherein the nickel flakes comprise athickness of less than about 5 microns.

235. The method of embodiment 233 or 234, wherein the nickel flakescomprise a diameter of about 500 nanometers to about 30 microns.

236. The method of any one of embodiments 214 to 235, wherein the nickelcomponent comprises a filamentary nickel powder.

237. The method of embodiment 236, wherein the filamentary nickel powdercomprises a longest dimension in a range of about 2 microns to about 10microns.

238. The method of any one of embodiments 214 to 237, wherein the nickelcomponent comprises at least one particle having a longest dimension ina range of about 100 nanometers to about 50 microns.

239. The method of any one of embodiments 216 to 238, wherein the carboncomponent comprises at least one of carbon flakes, carbonnano/microwires, and carbon spheres.

240. The method of any one of embodiments 216 to 239, wherein the carboncomponent comprises at least one of graphene, graphite, activatedcarbon, carbon nanotubes, and carbon nanofibers.

241. The method of embodiment 240, wherein the graphene comprisesgraphene flakes.

242. The method of embodiment 241, wherein at least one of the grapheneflakes comprises a diameter of about 5 microns.

243. The method of embodiment 241 or 242, wherein at least one of thegraphene flakes comprises a diameter of about 100 nanometers to about 50microns.

244. The method of any one of embodiments 240 to 243, wherein thegraphite comprises a graphite powder.

245. The method of any one of embodiments 214 to 244, wherein thepolycarboxylic acid component comprises a dicarboxylic acid.

246. The method of embodiment 245, wherein the dicarboxylic acidcomprises at least one of a propanedioic (malonic) acid, a butanedioic(succinic) acid, a pentanedioic (glutaric) acid, a hexanedioic (adipic)acid, a heptanedioic (pimelic) acid, a octanedioic (suberic) acid, anonanedioic (azelaic) acid, a decanedioic (sebacic) acid, anundecanedioic acid, a dodecanedioic acid, a tridecanedioic (brassylic)acid, a tetradecanedioic acid, a pentadecanedioic acid, ahexadecanedioic (thapsic) acid, an octadecanedioic acid, a maleic acid,a fumaric acid, a glutaconic acid, a traumatic acid and a muconic acid.

247. The method of any one of embodiments 214 to 246, wherein thepolycarboxylic acid component comprises a tricarboxylic acid.

248. The method of embodiment 247, wherein the tricarboxylic comprisesat least one of a citric acid, an isocitric acid, an aconitic acid, acarballylic acid, a trimesic acid, and a terephthalic acid.

249. The method of any one of embodiments 214 to 248, wherein thepolycarboxylic acid component comprises a hydroxicarboxilic acid.

250. The method of embodiment 249, wherein the hydroxicarboxilic acidcomprises at least one of a 4-hydroxybenzoic acid, a glycolic acid, alactic acid, citric acid, a mandelic acid, a beta hydroxy acid, an omegahydroxy acid, a salicylic acid, a 3-hydroxypropionic acid, and a6-hydroxynaphthalene-2-carboxylic acid.

251. The method of any one of embodiments 214 to 250, wherein the polyolcomponent comprises at least one of a glycerol and a glycol.

252. The method of any one of embodiments 214 or 251, wherein the polyolcomponent comprises at least one of a glycerin, a diol, a triol, atetraol, a pentaol, an ethylene glycol, a diethylene glycol, apolyethylene glycol, a propylene glycol, a dipropylene glycol, a glycolether, a glycol ether acetates 1,4-butanediol, a 1,2-butanediol, a2,3-butanediol, a 1,3-propanediol, a 1,4-butanediol, a 1,5-pentanediol,a 1,8-octanediol, a 1,2-propanediol, a 1,3-butanediol, a1,2-pentanediol, an etohexadiol, a p-menthane-3,8-diol, and a2-methyl-2,4-pentanediol.

253. The method of any one of embodiments 223 to 252, wherein theadditive component comprises at least one of a viscosity modifier, awetting agent, a flow and leveling agent, an adhesion promoter, and acorrosion inhibitor.

254. The method of embodiment 253, wherein the wetting agent comprises apolyethylene glycol.

255. The method of embodiment 253 or 254, wherein the corrosioninhibitor comprises at least one of an N,N-diethylhydroxylamine, anascorbic acid, a hydrazine, a hexamine, a phenylenediamine, abenzotriazole, a zinc dithiophosphate, a tannic acid, a zinc phosphate,and a hexafluoroacetylacetone.

256. The method of any one of embodiments 223 to 255, wherein theadditive component comprises a solvent.

257. The method of embodiment 256, wherein the solvent comprises atleast one of a viscosity modifier, a wetting agent, a flow and levelingagent and an adhesion promoter.

258. The method of any one of embodiment 256 or 257, wherein the solventcomprises at least one of an alcohol and water.

259. The method of embodiment 258, wherein the alcohol comprises atleast one of a methanol, an ethanol, a N-propanol, a butanol, pentanol,hexanol, an octanol, an N-octanol, a tetrahydrofurfuryl alcohol (THFA),a cyclohexanol, a cyclopentanol, and a terpineol.

260. The method of embodiment 259, wherein the N-propanol comprises atleast one of a 1-propanol, a 2-propanol, and a 1-methoxy-2-propanol.

261. The method of embodiment 259, wherein the butanol comprises atleast one of a 1-butanol and a 2-butanol.

262. The method of embodiment 259, wherein the pentanol comprises atleast one of a 1-pentanol, a 2-pentanol, and a 3-pentanol.

263. The method of embodiment 259, wherein the hexanol comprises atleast one of a 1-hexanol, a 2-hexanol, and a 3-hexanol.

264. The method of embodiment 259, wherein the N-octanol comprises atleast one of a 1-octanol, a 2-octanol, and a 3-octanol.

265. The method of any one of embodiments 223 to 264, wherein theadditive component comprises a butyl lactone.

266. The method of any one of embodiments 223 to 265, wherein theadditive component comprises an ether.

267. The method of embodiment 266, wherein the ether comprises at leastone of a methyl ethyl ether, a diethyl ether, an ethyl propyl ether, anda polyether.

268. The method of any one of embodiments 223 to 267, wherein theadditive component comprises a ketone.

269. The method of embodiment 268, wherein the ketone comprises at leastone of an acetone and a methyl ethyl ketone.

270. The method of embodiments 268 or 269, wherein the ketone comprisesat least one of a diketone and a cyclic ketone.

271. The method of embodiment 270, wherein the cyclic ketone comprisesat least one of a cyclohexanone, a cyclopentanone, a cycloheptanone, acyclooctanone, a benzophenone, an acetylacetone, an acetophenone, acyclopropanone, and an isophorone.

272. The method of any one of embodiments 223 to 271, wherein theadditive component comprises an ester.

273. The method of embodiment 272, wherein the ester comprises at leastone of a dibasic ester, an ethyl acetate, a dimethyl adipate, aproplyene glycol monomethyl ether acetate, a dimethyl glutarate, adimethyl succinate, a glycerin acetate, and a carboxylate.

274. The method of any one of embodiments 223 to 273, wherein theadditive component comprises a carbonate.

275. The method of embodiment 274, wherein the carbonate comprises apropylene carbonate.

276. The method of any one of embodiments 223 to 275, wherein theadditive component comprises at least one of a glycol ether, a glycolether acetate, a tetramethyl urea, an n-methylpyrrolidone, anacetonitrile, a tetrahydrofuran (THF), a dimethyl formamide (DMF), anN-methyl formamide (NMF), a dimethyl sulfoxide (DMSO), a thionylchloride, a sulfuryl chloride, a 1,2-diaminoethane, apropane-1,3-diamine, a butane-1,4-diamine, a pentane-1,5-diamine, ahexane-1,6-diamine, a 1,2-diaminopropane, a diphenylethylenediamine, adiaminocyclohexane, an o-xylylenediamine, an o-phenylenediamine, anm-phenylenediamine, a hexane, a decane, a teradecane, a styrene, a1-vinyl-2-pyrolidone, a toluene, a pyridine, and a triethyl phosphate.

277. The method of any one of embodiments 214 to 276, wherein theconductive ink has a viscosity at about 25° C. in a range from about5,000 centipoise to about 11,000 centipoise.

278. The method of any one of embodiments 214 to 277, wherein the nickelcomponent is in a range from about 50 wt % to about 60 wt %.

279. The method of any one of embodiments 214 to 277, wherein the nickelcomponent is in a range from about 35 wt % to about 65 wt %.

280. The method of any one of embodiments 216 to 279, wherein the carboncomponent is in a range from about 0.5 wt % to about 2.5 wt %.

281. The method of any one of embodiments 216 to 279, wherein the carboncomponent is less than about 10 wt %.

282. The method of any of embodiments 214 to 281, wherein thepolycarboxylic acid component is in a range from about 5 wt % to about15 wt %.

283. The method of any of embodiments 214 to 282, wherein the polyolcomponent is in a range from about 25 wt % to about 40 wt %.

284. The method of any of embodiments 214 to 282, wherein the polyolcomponent is in a range from about 15 wt % to about 60 wt %.

285. The method of any of embodiments 223 to 284, wherein the additivecomponent is less than about 10 wt %.

286. A printed conductive nickel film using a nickel ink fabricatedaccording to a method of any one of embodiments 214 to 285.

287. A conductive nickel film of any one of embodiments 58 to 79, and286, wherein the conductive film has a sheet resistance of less thanabout 1.5 Ohms per square per mil (Ohms/sq/mil).

288. The conductive nickel film of embodiment 287, wherein theconductive film has a sheet resistance of less than about 1.0Ohms/sq/mil.

289. A conductive nickel film of any one of embodiments 58 to 79, and286 to 288, wherein the conductive film has a surface roughness of lessthan about 10.

290. A conductive nickel film of any one of embodiments 58 to 79, and286 to 289, wherein the conductive film has polar liquid phobicity.

291. The conductive nickel film of embodiment 290, wherein theconductive film has hydrophobicity.

292. A conductive nickel film of any one of embodiments 58 to 79, and286 to 291, wherein the conductive film has an adhesion value of lessthan 3.

293. A conductive nickel film of any one of embodiments 58 to 79 and 286to 292, wherein the conductive film has a viscosity of about 9,000centipoise (cP) at a temperature of about 25° C.

294. A conductive ink comprising:

-   -   a nickel component;    -   a polycarboxylic acid component; and    -   a polyol component, the polycarboxylic acid component and the        polyol component being reactable to form a polyester component.

295. The conductive ink of embodiment 294, wherein the nickel componentcomprises nickel flakes.

296. The conductive ink of embodiment 294 or 295, wherein thepolycarboxylic acid component comprises glutaric acid and the polyolcomponent comprises ethylene glycol.

297. The conductive ink of any one of embodiments 294 to 296, wherein anickel film printed using the conductive ink has a sheet resistance ofabout 0.4 Ohms per square per mil (Ohms/sq/mil) to about 0.5Ohms/sq/mil.

298. The conductive ink of any one of embodiments 294-297, furthercomprising a polar liquid phobicity additive.

299. The conductive ink of embodiment 298, wherein the polar liquidphobicity additive comprises dimer diamine.

300. The conductive ink of any one of embodiments 294 to 299, furthercomprising a printability enhancing additive.

301. The conductive ink of embodiment 300, wherein the printabilityenhancing additive comprises styrene.

302. The conductive ink of embodiment 300 or 301, wherein theprintability enhancing additive further comprises a peroxide.

303. The conductive ink of embodiment 302, wherein the peroxidecomprises at least one of a benzoyl peroxide, a 2-butanol peroxide, a2,4-chlorobenzoyl peroxide, and a lauryl peroxide.

304. The conductive ink of any one of embodiments 294 to 303, whereinthe polycarboxylic acid component comprises at least one of a maleicacid, a fumaric acid, a glutaconic acid, a traumatic acid and a muconicacid.

305. The conductive ink of any one of embodiments 294 to 304, whereinthe polyol component comprises an unsaturated diol.

306. The conductive ink of any one of embodiments 294 to 305, whereinthe polyester component comprises an unsaturated polyester component.

307. The conductive ink of any one of embodiments 294 to 306, whereinthe conductive ink further comprises graphene flakes.

308. A method of fabricating a conductive ink, the method comprising:

-   -   dispersing a nickel component in a polyol component; and    -   dispersing a polycarboxylic acid component in the polyol        component, the polycarboxylic acid component and the polyol        component being reactable to form a polyester component.

309. The method of embodiment 308, wherein the polycarboxylic acidcomponent comprises glutaric acid and the polyol component comprisesethylene glycol.

310. The method of embodiment 308 or 309, wherein the nickel componentcomprises nickel flakes.

311. The method of embodiment 310, further comprising removing nickeloxide from one or more surfaces of the nickel flakes.

312. The method of embodiment 311, wherein removing the nickel oxidecomprises heating the nickel flakes in the presence of thepolycarboxylic acid component.

313. The method of embodiment 312, wherein heating comprises heating thenickel flakes and the polycarboxylic acid component to a temperature ofabout 80° C. to about 120° C.

314. The method of any one of embodiments 308 to 313, further comprisingadding a polar liquid phobicity additive.

315. The method of embodiment 314, wherein the polar liquid phobicityadditive comprises dimer diamine.

316. The method of any one of embodiments 308 to 315, further comprisingmixing the nickel component with mixing media for reducing a nickelcomponent particle size, wherein the mixing media comprises beads.

317. The method of embodiment 316, wherein the beads comprise zirconiabeads having a diameter of about 0.3 millimeters (mm) to about 10 mm.

318. The method of embodiment 317, further comprising mixing the nickelcomponent with the zirconia beads for a duration of between about 1 hourand about 2 days.

319. The method of any one of embodiments 316 to 318, further comprisingmixing the mixing media and the nickel component in a jar mill.

320. The method of embodiment 319, wherein the jar mill has a diameterof about 3 inches to about 15 inches.

321. The method of embodiment 319 or 320, further comprising rotatingthe jar mill at a rotation speed of about 50 revolutions per minute(RPM) to about 200 RPM.

What is claimed is:
 1. A conductive ink comprising: a conductive nickelcomponent; a conductive carbon component; and a printability enhancingadditive, wherein the printability enhancing additive comprises aperoxide.
 2. The conductive ink of claim 1, wherein the conductivenickel component comprises nickel flakes.
 3. The conductive ink of claim2, wherein the nickel flakes comprise a longest dimension of 10 μm to 15μm.
 4. The conductive ink of claim 1, wherein the conductive carboncomponent comprises graphene flakes.
 5. The conductive ink of claim 1,wherein the printability enhancing additive further comprises styrene.6. The conductive ink of claim 1, wherein the peroxide is selected fromthe group consisting of benzoyl peroxide, 2-butanol peroxide,2,4-chlorobenzoyl peroxide, lauryl peroxide, and a combination thereof.7. The conductive ink of claim 6, wherein the peroxide comprises benzoylperoxide.
 8. The conductive ink of claim 1, further comprising apolycarboxylic acid component and a polyol component, the polycarboxylicacid component and the polyol component being reactable to form apolyester component.
 9. The conductive ink of claim 8, wherein thepolycarboxylic acid component comprises at least one of maleic acid,fumaric acid, glutaconic acid, traumatic acid, and muconic acid.
 10. Theconductive ink of claim 8, wherein the polycarboxylic acid componentcomprises glutaric acid and wherein the polyol component comprisesethylene glycol.
 11. The conductive ink of claim 1, wherein a nickelfilm printed using the conductive ink has a sheet resistance of 0.4 Ohmsper square per mil (Ohms/sq/mil) to 0.5 Ohms/sq/mil.
 12. A method offabricating a conductive ink, the method comprising: providing a mixturecomprising a conductive nickel component and a conductive carboncomponent; and dispersing a printability enhancing additive in themixture, wherein the printability enhancing additive comprises aperoxide.
 13. The method of claim 12, wherein the conductive nickelcomponent comprises nickel flakes.
 14. The method of claim 13, furthercomprising removing nickel oxide from one or more surfaces of the nickelflakes.
 15. The method of claim 14, wherein removing the nickel oxidecomprises heating the nickel flakes in the presence of a polycarboxylicacid component to a temperature between 80° C. and 120° C.
 16. Themethod of claim 12, wherein the printability enhancing additive furthercomprises styrene.
 17. The method of claim 12, further comprising mixingthe conductive nickel component with mixing media and reducing aconductive nickel component particle size, wherein the mixing mediacomprises beads.
 18. The method of claim 12, wherein providing themixture comprises: dispersing the conductive nickel component in apolyol component; dispersing a polycarboxylic acid component in thepolyol component, the polycarboxylic acid component and the polyolcomponent being reactable to form a polyester component.